The invasion of Poland on the 1 September 1939 by Nazi Germany heralded the start of another general European war, which quickly became a global conflict with the declaration of war by Britain and France as well as their respective empires, two days later. The outcome of this campaign was virtually a foregone conclusion as it pitied the newly modernised armed forces of Central Europe's major industrial power against the smaller, less technologically advanced forces of its eastern neighbour, a country that had only achieved independence again after the end of the First World War. To further complicate the balance of power, Nazi Germany had entered into a non-aggression agreement with the USSR (also known as the Molotov-Ribbentrop Pact) about a week before, the announcement being made on 25 August 1939 in a move that stunned the world. As part of this agreement, the Red Army invaded Poland two weeks after the start of the German invasion, guaranteeing that Poland would be partitioned between the two powers.
The Polish campaign also heralded a new style of warfare, representing the first demonstration of what is now known as Blitzkrieg. During the 1930s, Germany successfully blended the tactical lessons of the First World War with some of the technological innovations that had first made an appearance towards the end of that conflict and further developed during the 1920s and 1930s. These innovations included the use of armoured fighting vehicles, mobile artillery, monoplane combat aircraft and reliable radio communications, which were merged to create a devastating new form of combined arms warfare. In this case, the German invasion was spearheaded by units of tanks (the Panzer divisions) and supported by dive bombers (Stukas), artillery and motorised infantry (panzer grenadiers).
However, the Polish Army was not as backward or inferior as is often portrayed, its stubborn and spirited defence occasionally giving the Germans a nasty surprise. Despite what is now known as the "shock and awe" factor, the Germans had not yet perfected their new tactics and suffered heavy casualties for what was a relatively short campaign. Despite this, the campaign proved to be a valuable learning experience for the Wehrmacht, which uncovered a number of shortcomings in both training and doctrine. This made it possible for the Wehrmacht to perfect the tactics of Blitzkrieg, as well as testing new theories on the use of armoured forces and the close air support of ground troops before their next great challenge, the invasion of France and the Low Countries in May of the following year. The complete destruction of the Polish state, the dismemberment of its armed forces and the effective removal of Poland from the map of Eastern Europe were to be grim portents as to the fate of the other occupied territories in this new concept of total war.
The longer term background to the campaign lies in Poland's geo-strategic position, while the more immediate causes lie in the German defeat in the First World War and rise to power of Adolf Hitler and the NSDAP (National Sozialistische Deutsche Arbeiter Partei – National Socialist German Workers Party) in the early 1930s.
Poland began to form as a unitary state in the middle of the 10th Century under the Piast Dynasty and in the late 14th Century, formed a union with Lithuania. This Commonwealth eventually collapsed after a period of war, famine and disease leading to the three partitions of Poland (1772, 1793, and 1795) which culminated in Poland being erased from the map of Europe and its territories being divided between Russia, Prussia and Austria. Indeed, it would be these three countries that would control Poland's destiny until the revolutions of 1989. The Poles however didn't take to having their territory controlled by foreign governments so regularly revolted. Napoleon I temporarily set up an independent Poland known as The Grand Duchy of Warsaw but which was again divided by the victorious Allies in 1815, the majority gradually being annexed by the Russian Empire under the Tsar. During the First World War, Polish territory saw extensive fighting between Germany and Austria Hungary on the side of the Central Powers, against Russia on the side of the Allies. Over two million Polish troops fought with all three countries with around 450,000 being killed. The war saw both sides trying to harness Polish nationalist feeling and it was the Allies, in particular the United States under Woodrow Wilson's Fourteen Points, who fully promoted the idea of a newly independent Poland. This became a reality on 11 November 1918 under Józef Piłsudski (the general who commanded Polish troops under the Austro-Hungarians) who invited Polish exiles to return from abroad, with Ignance Paderewski forming a coalition government on 17 January 1919. The new Polish state started its existence in exceptionally difficult circumstances. Having been the scene of extensive fighting and with many of its factories either destroyed or idle, its agriculture devastated and economy in chaos. Reconstruction and recovery would take much longer than most of the other participants in the First World War. Poland's northwestern and western borders were fixed by the Treaty of Versailles signed between the Allies and Germany on 28 June 1919. Its southern border was fixed by the Treaty of St Germain between the Allies and Austria Hungary, signed 10 September 1919 and its eastern border established after winning a conflict fought with the newly established Soviet state, settled by the Treaty of Riga on 18 March 1921.
The rise to power by Hitler and the Nazi Party was helped hugely by the deep sense of humiliation and despair that Germany felt after the defeat of the First World War. Despite seeking an armistice on the understanding that any settlement would be based on Wilson's Fourteen Points, the actual settlement terms imposed by the Allies were harsh with Germany not only loosing her overseas colonies but large areas of Germany itself being transferred. These were given back to Russia and France (Alsace-Lorraine), given to Belgium (Eupen and Malmedy – despite a plebiscite to the contrary) and Denmark (Schleswig-Holstein) or used to help create new states, such as Poland (Upper Silesia, West Prussia and Posen) and Czechoslovakia (Hultschin). In many of these areas, ethnic Germans suffered harassment and discrimination at the hands of their new masters. For example, of the 1,058,000 ethnic Germans in the West Prussia – Posen area in 1921, almost 760,000 had fled their homes within five years. In addition, the Saar, Danzig and Memel were to be controlled by the League of Nations (Danzig eventually became a free city in order to create the Polish Corridor, Memel was annexed by Lithuania while the Saar eventually voted on 13 January 1935 to reintegrate with Germany), the Rhineland made into a Demilitarised Zone, the German Army limited to 100,000 men and the Navy to six capital ships with no submarines. No Air Force was allowed. On top of that, Germany had to accept Clauses 231 – 248 (the infamous 'war guilt' clauses), which stated that she had to accept full responsibility for the outbreak of the First World War and as a consequence, pay for all the damage caused by the conflict, a figure not determined at the Versailles conference itself but only later, which was finally put at £6.6bn or $33bn in 1921 (equivalent to £218bn or $400bn in 2008), well beyond Germany's ability to pay, placing a significant burden on its economy, which itself was struggling to recover. While Germany's first democratically elected Chancellor, Philipp Scheidemann, refused to sign the Treaty and resigned, the head of the new coalition Government, Gustav Bauer was told that the Army was in no position to resist any form of foreign occupation and so recommended that it be signed, which it was on 28 June 1919 and ratified by the National Assembly on 9 July 1919. This was opposed by many in the military hierarchy, conservatives and nationalists who viewed anyone who had anything to do with this act with suspicion and led to the 'stab in the back' myth, whereby Germany had been let down by elements on the domestic front who had conspired to disrupt the war effort for their own ends. Such groups were viewed as including communists, Jews, socialists and members of the Weimar Republic political apparatus.
Such sentiments were fully exploited by the Nazis in their rise to power and tensions increased due to their racial ideology that linked the growth in power of the German nation to the seizure of 'lebensraum' (living space) from the Slavic nations to the east (who were effectively viewed as sub-humans). After seizing power in 1933, Hitler began Germany's rearmament with the introduction of universal military conscription, the expansion of both the Army (Heer) and Navy (Kriegsmarine) as well as the formal re-establishment of the Air Force (Luftwaffe). By the late 1930s, he was ready to use Germany's growing military might to further his political and territorial ambitions. This began with the re-occupation of the Rhineland in March 1936, continued with the 'anschluss' with Austria in March 1938 and in the seizure of the Sudetenland from Czechoslovakia in September 1938 after the Munich Conference finally culminating with the occupation of the remainder of Czechoslovakia in March 1939. The appeasement of Germany at the Munich Conference led Hitler to view the West (in particular France and the UK) as weak who could be bullied into further territorial concessions. It convinced Stalin, that when push came to shove, the UK and France would not back up their military commitments to the countries of Central and Eastern Europe (both France and the Soviet Union had had military-assistance treaties with Czechoslovakia) with action. The only alternative was to seek an accord with Germany separately. In parallel with Germany, Russia had lost territory after the First World War to the newly formed states in Central and Eastern Europe and so shared a desire to rectify the situation.
At the time, both the UK and France viewed the Munich Agreement with relief and it was hailed by Neville Chamberlain (the British Prime Minister at the time) as guaranteeing 'peace for our time'. By early 1939 however, their view had changed and began to recognise that Hitler's territorial demands would be insatiable. Their attitude gradually hardened and they resolved to confront the Nazi menace, particularly after Germany occupied the remainder of Czechoslovakia. Such territorial demands next manifested themselves with regard to Poland. In late March 1939, Hitler told his chiefs of staff that the 'Polish Question' would have to be solved by military means. The main irritant was the territorial losses to Poland after the First World War, including the corridor in Pomerania and Silesia that gave Poland access to the Baltic Sea and separated East Prussia from the rest of Germany that contained the free port of Danzig. In October 1938, Hitler had started putting pressure on Poland to permit the construction of an extra-terrestrial road that would link East Prussia with the rest of Germany as well as the re-establishment of sole German control over Danzig. Such pressure was resisted by the Poles, who quite rightly viewed them as pretexts for further territorial claims, most probably at Poland's expense. Poland had viewed the agreement over the Sudetenland with alarm, in case the same thing happened over the Polish Corridor and Danzig but on 31 March 1939, the UK announced its guarantee of Polish security, including maintaining the status quo over Danzig. The Soviet Union had been excluded from these discussions, as the Poles had an understandable concern that any Soviet military intervention in the area would amount to a virtual occupation. Although both the UK and France were interested in involving the Soviet Union in an anti-German alliance, they could not overcome Poland's suspicions over Moscow's long term aims. The German diplomatic successes in 1938 and early 1939 along with the apparent vacillation and weakness of the UK and France led Stalin to consider concluding a treaty with Germany. If Germany was going to seize territory the Soviet Union might as well follow suit. Much of Eastern Poland was owned by Russia after the partitions of the 18th Century until 1918 and the high numbers of Byelorussians and Ukrainians provided a pretext for reintegration. Stalin also desired control over former Imperial Russian territories including Moldova, the Baltic States and parts of Finland. In the summer of 1939, the German ambassador in Moscow began informal talks with the Soviets about a possible treaty. This culminated on 25 August 1939 with the Ribbentrop – Molotov Pact. This signing of a non-aggression pact stunned the world, given that the Soviet Union and Nazi Germany were diametrically opposed ideologically. For both Hitler and Stalin however, it was always a marriage of convenience, something that would become apparent a mere twenty-two months later.
The pact gave Hitler the green light for the invasion of Poland. He was certain that it was he, and he alone, who represented the will of the German people and could rally the nation to war. He was convinced that both the UK and France would try and avoid going to war and even if a response was forthcoming, it would be weak and indecisive. It was likely however, that the final confrontation would be with these two countries however, and so before that, the Wehrmacht would have to prove itself in battle. Poland presented the ideal opportunity as its strategic position between both Germany and the Soviet Union virtually guaranteed its destruction. On 23 August 1939, Hitler presented his plan to OKW (Oberkommando der Wehrmacht – the Chiefs of Staff for the Armed Forces) for the invasion of Poland, originally scheduled for 26 August 1939. The British pledge of military support made Hitler hesitate and attempt further diplomatic moves to isolate Poland and invent a border incident to further discredit them. The commanders told Hitler that their forces could not indefinitely be held at such a high state of readiness at their jumping off points without losing the element of surprise and so the invasion was scheduled for 1st September 1939.
The mobilisation and deployment of German forces had to be discrete so as not to complicate the diplomatic moves being made in August. The first stage began on 26 June with the transfer on nine infantry divisions to the east. The second phase, involving thirteen divisions, began on 3 August and was disguised as normal summer manoeuvres. It included the first major movement of forces into East Prussia and was disguised as manoeuvres by the East Prussian 1st Army Corps and the annual Tannenberg celebrations (the victory in the First World War, of which 1939 would be the 25th anniversary). The next phase began on the 19 August for all formations that were six days or more away from their assembly areas (remembering that the initial date was to have been 26 August).
In early 1939, Poland began to re-examine its plans for a potential war with its powerful neighbour. Like many small countries, Poland devoted a great deal of effort to intelligence gathering and (unlike the Germans vis-a-vis Poland) had quite an effective human- and signals-intelligence network. The Poles had in fact broken the German Enigma tactical coding system but the German addition of another element to the system in the summer of 1939 cut this off as a source of intelligence. Nevertheless, the Poles had a reasonable view of both the German tactical dispositions and the likely plan of attack. A new war plan, codenamed Plan Z (Zachod - West) was submitted in March 1939. This estimated that the Germans could put together around 110 divisions, with about seventy committed to the attack on Poland, before being moved west. This plan was modified after the seizure of Czechoslovakia to take account of the likelihood that the main thrust would now be from Silesia. Indeed, the Poles had met the French with a eye to discuss joint action in case of an attack in May 1939, where the Poles left with the notion that the French would attack Germany with around thirty-eight divisions within two weeks of an attack on Poland. However Gamelin and the French General Staff had in fact no detailed plans for such an attack, and on 31 May 1939, a directive changed the scope of this operation to a 'feeling out' one. The Poles were never told of this change but the French expected the Poles to hold out for several months, enough time for a plan to be formulated and put into practice.
The misconception that France would quickly come to their aid lay at the heart of their defence planning. The Poles looked at two options – the first looked at utilising the bold Russian defensive lines on the Biebrza, Narew, Vistula and San Rivers. While this was in line with Polish doctrine and would not over-extend the limited Polish force structure of thirty divisions, it relied on the army being fully mobilised. Given that a large proportion of the manpower would come from the western provinces, if the Germans struck before the mobilisation plan could be completed, the Polish Army would lose a lot of its manpower very early on. There was also concern that if Poland's defences were far to the east, the Germans would seize the Pomeranian Corridor and areas adjacent to it without a fight, just as they did with the Sudetenland. The second option was to position Polish forces west of the river lines near the frontier. Assuming it would take a couple of weeks to fully mobilise the army, the defence of this sector would shield the mobilisation of forces in the most populated areas of Poland, especially important as Poland was quite ethnically and culturally diverse, with only about sixty percent of the population being Polish. A strong defence of the western provinces would also oblige France and the UK to act and declare war.
The Poles were under no illusions about their prospects against the much larger and better equipped Wehrmacht – their only hope was to prolong the fighting long enough for the British and French to strike Germany from the West. They therefore planned to place the bulk of their forces in western Poland – a move misunderstood by some to be following a linear defence similar to France – to shield the provinces there for as long as possible to enable mobilisation and a gradual withdrawal eastwards to prolong the war by avoiding a decisive battle. Polish doctrine was based on the 1920s war with Russia which had been primarily a war of manoeuvre. Of course, the major problems with this were:
1. This disposition of forces meant that the infantry divisions were covering sectors far beyond what was deemed prudent in Polish tactical doctrine. This meant that the forward Polish formations were unable to slow the Germans without becoming decisively engaged and ultimately destroyed by the much larger and more powerful German formations.
2. They seriously underestimated the pace of combat. Even though they planned for a war of manoeuvre, they failed to appreciate the impact of mechanisation in that the low density of understrength Polish formations meant that the main line of resistance was almost always penetrated and that the Wehrmacht had the capability to exploit the situation far faster than the Poles could react.
3. Ultimately, the Poles were in a tight spot. The river defence option, while military sound, did not address the political and strategic dilemmas. The forward defence plan, while addressing said dilemmas, was militarily unsound. The situation became even worse with the announcement of the Molotov-Ribbentrop Pact in late August.
The Treaty of Versailles, signed at the end of World War One, limited the German Armed Forces to a relatively small force of long-term volunteers. Conscription was not permitted, neither were any offensive weapons such as aircraft, tanks or submarines. It was in fact, little more than a police and coastal patrol force and would need considerable reinforcement even if wanted to fight a defensive campaign within the Reich itself against one of its stronger neighbours.
The Army was allowed a strength of 100,000 men including 4,000 officers. Non-Commissioned Officers and enlisted men were to serve twelve years while officers would serve twenty-five years. A further condition imposed by the Allies was that no more than five percent of the force could be released in a single year by terminating their service. These restrictions effectively prevented the creation of a reserve of any decent size. No field pieces larger than 105mm were to be used, with the exception of a few fixed pieces in the fortress of Konigsberg in East Prussia. The Navy was authorised to have 15,000 men, including 1,500 officers. Six older battleships, six light cruisers, twelve destroyers and twelve torpedo boats were permitted in the fleet, with two battleships, two cruisers, four destroyers and four torpedo boats in reserve. The building of ships displacing over 10,000 tons was prohibited and naval guns were restricted to 280mm (11 inches) or less. What is termed 'defence industry' today (weapons and munitions manufacturing) was reduced to the minimum necessary to maintain authorised stocks. For example, a complete small arms factory was sold to the Czech weapons firm CZ which set it up in Brno. No German troops were allowed in a demilitarised zone extending thirty-one miles (fifty kilometres) east of the Rhine and Allied Control Commissions were to be allowed to inspect any defence-related formation or institution to check compliance.
This situation took place against the backdrop of the establishment of the Weimar Republic under President Ebert (Germany had become a republic with the abdication of the Kaiser in November 1918). The new organisation, based upon many of the recommendations of Generalleutnant Hans von Seekt, became known as the Reichswehr (Reichs Defence Force) and was formed after the Defence Law of 23 March 1923, being made up of the Reichsheer (Army) and Reichsmarine (Navy). The nominal head of the armed forces was the President but actual authority lay in the Defence Minister, a member of the President's cabinet. As could be expected, a large number of officers and NCOs were available with experience to command this force initially, but as time went on, emphasis was given over to recruiting younger men. Forced to make the best they could with small numbers, the Germans proceeded to try and form an elite force with incentives to recruit high calibre personnel, pay was increased and barrack conditions improved. Strict discipline gained the Reichswehr respect from the civilian population and relations in garrison and port towns were usually good. There was also a concerted effort to take over many of the traditions formerly held by formations in the Imperial Army. The Chief of Staff for the Army was known as the Chief of the Army Command (Chef der Heeresleitung) and had five departments under his command, the most important being the Truppenamt, a general duties section that took over many of the functions of the old Imperial General Staff (which had been disbanded in compliance with the Versailles Treaty). The actual ground formations of the army consisted of seven small infantry divisions numbered 1 through 7 and three cavalry divisions, numbered 1 to 3. Each infantry division consisted of about 12,000 men, with three infantry regiments, an artillery regiment as well as reconnaissance, signal, engineer, transport and medical battalions. Each cavalry division had about 5,300 men in six small cavalry regiments and an artillery battalion. Each commander of an infantry division had a dual responsibility – each commanded one of the seven military districts (Wehrkreise) numbered I through VII.
Over time, the Germans managed to evade some of the restriction of the Versailles Treaty by establishing military installations and armaments factories in the Soviet Union. These arrangements were tacitly supported by the German Government, financed by many of the large industrial firms such as the Junkers Aircraft Corporation, and welcomed by the Russians themselves, who were desperately seeking foreign scientists and engineers to help build up their own air and tank arms, as well as a chemical warfare service. In return for technical advice and the services of the German experts, the Russians allowed the Germans to test weapons and equipment and train cadres of personnel unhindered by the Allied Control Commissions. Also, many of the restrictions imposed by the Versailles Treaty were relaxed or simply not enforced, and so the Reichswehr began to build up its anti-aircraft, artillery and other weapons. They also took advantage of where the Treaty was ambiguous, for example, there was nothing stopping the actual designing of new weapons, so plans and blueprints were made for new weapons, tanks and aircraft.
By 1930, the Army felt secure enough to start planning work to prepare for an expansion of the Army in time of war. It was planned that the seven infantry divisions would expand to twenty-one. Millions of Great War veterans were available to fill the ranks of these divisions, but these people were getting older, and there was no training available for the German youth apart from the Reichsheer and police forces. Arms and equipment would be available for two thirds of this force but ammunition would be in short supply. Further studies were started in 1932 to look at the gradual expansion of arms and munitions plants to fulfil these needs. In addition to the infantry divisions, the cavalry divisions would be filled out and an extra division formed, there would be thirty-three batteries of heavy artillery, fifty-five batteries of anti-aircraft guns, a small army air force and a tank battalion. These plans were interrupted by the appointment of Adolf Hitler as Chancellor.
The Navy on the other hand had much greater difficulty in evading the Treaty restrictions than did the Army. There were no Treaty restrictions on replacing old ships, so as soon as the post-war situation had settled, the Navy began a limited construction programme, even though it was thoroughly scrutinised by the Allied Control Commission. A serious problem was the retention of knowledge, skills and experience of both the crews and the engineers that built the vessels, especially those related to submarines. One way around this was to either build submarines for export to foreign governments (for example, Japan) or to send these personnel abroad to work on construction programmes in foreign countries, such as the Netherlands, Finland and Spain. These enterprises needed funding initially but soon became self-sustaining enterprises. Towards the end of the 1920s, when things began to relax, many of these operations were brought back to the Reich and construction facilities for six U-Boats were built at Kiel and component parts for twelve submarines kept in storage. The Germans also kept up their lead in fire control equipment – a trainload had been moved into hiding in Venlo and shipped back gradually. Later, the Navy purchased a Dutch precision engineering firm to carry out experimental work on fire control and other technical equipment. The Navy still had three per-World War One battleships, the Hannover (1905), Schleisien (1906) and Schleswig-Holstein (1906) but under the warship replacement programme, a design of new armoured cruisers was developed (10,000 tons and 11-inch guns, also called 'pocket battleships') and three were eventually built – Deutschland (1931), Admiral Scheer (1933) and Graf Spee (1934). Six light cruisers were also built – Emden (1925), Konigsberg and Karlsruhe (1927), Koeln (1928), Leipzig (1929) and Nuernberg (1934). The Emden displaced 5,400 tons, the rest displaced 6,000 tons. All had 5.9-inch guns. Two new battleships (or battle cruisers according to some sources) were planned but building was delayed as they displaced 26,000 tons and had 11-inch guns.
Military aviation had been completely prohibited under the Treaty of Versailles and German civil aviation was delegated to the Air Office in the Ministry of Transport in the immediate post-war years. It wasn't until 1922 that the construction of civil aircraft was allowed and even then there were restrictions as to weight, ceiling, speed and horsepower. Despite this, the German aviation industry managed to keep its proficiency during the 1920s and the public's interest in aviation generally was kept up by gliding clubs and other aviation-minded organisations. Again, over time, these restrictions were gradually relaxed, especially after 1926. The number of officers able to receive flying training increased from five to seventy-two and the restrictions on civil aircraft construction were lifted. Several small corporations amalgamated to form Lufthansa and quickly established routes all over Europe. The nucleus of the future Luftwaffe was quickly formed within Lufthansa and by 1931 the 'secret' air force totalled four fighter, eight observation and three bomber squadrons. Basic flight training was carried out within Lufthansa but tactical training was necessarily restricted, although a certain amount of training was carried out in the USSR. This, plus the fact that doctrine was generally centred upon the defensive with an air arm as part of the Army meant that there was no real possibility of building a foundation upon which the formation of a proper air force could take place until after Hitler had taken power. By 1933 however, production facilities had improved much more, with Messerschmitt already producing light aircraft, Focke-Wulf had established itself at Bremen, Junkers was developing one of the largest aircraft factories in Europe at Dessau, Heinkel had a large plant in Warnemuende and Dornier had a number of factories abroad.
After Hitler had become Chancellor on 30 January 1933 and assumed absolute power after the passing of the Enabling Law on 23 March, he embarked upon a gradual but remorseless expansion of the armed forces (and defence industry) so as to bring Germany back on level terms with the other Great Powers and to enable him to implement his intentions in foreign policy. On 14 October Germany withdrew from the disarmament conference being run by the League of Nations. Some of the more extreme elements of the Nazi Party including members of the SA – Sturmabteilungen – wanted to absorb the Reichsheer causing a conflict within the new Government. Hitler came down upon the side of the Reichsheer and on 30 June 1934 (The Night of the Long Knives) Hitler effectively decapitated the SA and also used the opportunity to rid himself of a number of political opponents. Upon Hindenburg's death on 2 August 1934, Hitler assumed the title of Fuhrer and Reich Chancellor with the office of the President being abolished, becoming both the Head of State and Commander-in-Chief of the Armed Forces and requiring all officers and men of the armed forces to swear a personal oath of obedience to him, a departure from the oath of allegiance to the state as required under the Weimar Republic. The strength of the army had risen to 240,000 by the end of 1934 and Hermann Göring becoming Air Minister as a prelude to the unveiling of the new air force. Erhard Milch became his deputy and immediately set to work expanding production. Milch's calculations showed that the air force would need eight to ten years to build up an adequate nucleus for the new service, but political considerations would soon intervene.
Hitler publicly denounced the clauses of the Versailles Treaty on 16 March 1935. At the same time, he introduced a new defence law that expanded the army to twelve corps and thirty-six divisions, as well as reconstituting conscription. An additional law, dated 21 May 1935 brought the Luftwaffe into the open and established it as a separate service. It also set the period of training for conscripts at one year. This was necessitated by the lack of an established cadre of personnel. By late 1936, the expansion of the Wehrmacht was such that it could be extended to two years but for now, conscription offices took the details of men from the class of 1914 (who were born in that year), First World War veterans still within military age limits (eighteen to forty-five, except East Prussia where the upper limit was fifty-five) and the large group of men born between 1901 and 1913. These would pose a special problem as few had had military training but it was from this group that a large part of the reserve would be drawn and those nearer the beginning of the turn of the century were starting to become a little old to start military training. So many were given two or three months training and assigned to the new reserve divisions which would be used in a defensive role or some form of security capacity, or to various support units.
The population and industrial base already existed to support an enlargement of the armed forces. Prior to the annexation of Austria and the Sudetenland (Czechoslovakia), the Reich's population had been close to 70 million and with the addition of these areas, the population increased by some 10 million. In addition, it produced over 22 million tons of steel and 200 million tons of coal annually, was highly developed industrially with large motor and tool plants and an excellent transportation system as well as having a merchant marine with over 4 million tons and excellent port facilities.
The German armed forces, formerly the Reichswehr, were renamed the Wehrmacht, with the Reichsheer becoming the Heer (Army), the Reichsmarine becoming the Kriegsmarine (Navy), the air force being named the Luftwaffe, the Truppenamt becoming the Army General Staff and the Defence Minister becoming the Minister for War (Generaloberst Werner von Blumberg). The Kriegsmarine remained under the command of Grossadmiral Erich Raeder and the Luftwaffe was headed by Hermann Goring, now a General der Flieger. A scandal would later mean both Bloomberg, and the C-in-C Armed Forces (General der Artillerie Werner von Fritsch) resigning with Hitler exercising complete control through a new headquarters, formed in February 1938 – OKW (Oberkommando der Wehrmacht – High Command of the Armed Forces) with General der Artillerie Wilhelm Keitel becoming its Chief of Staff. To this reported the high commands of the various services, the OKH (Oberkommando des Heeres - Army High Command under Generaloberst Walter von Brauchitsch), OKM (Oberkommando der Marine - Naval High Command) and OKL (Oberkommando der Luftwaffe - Air Force High Command). There was no concrete division of responsibilities between the OKW and the service high commands, with a result that friction between them increased considerably, with the head of the services increasingly going to Hitler directly.
However, all was not going smoothly. The expanding services were growing at such a rate (including the building of new barracks, depots, headquarters, repair and maintenance facilities, airfields etc.), especially the Army, that concessions had to be made to practicalities. There were still too few officers from the Reichswehr to command all the new units, a situation made worse by the loss of a large number of experienced officers and NCOs to the Luftwaffe, although some relief was had by incorporating militarised police units into the army. The requirements for officers were lowered and thousands of former Reichswehr NCOs became junior officers, and thousands of enlisted men became NCOs. All this could still not plug the gap, so thousands of World War One veterans were called up, until such time as younger men could be trained. There were also problems with production. There were so many requirements for additional tanks, armoured fighting vehicles, small arms, artillery, aircraft and warships that there proved to be insufficient raw materials and labour to build all this new equipment. As a result, the Navy was forced to curtail its ambitious plans for expansion for the sake of the Army and Air Force and concentrated instead (apart from major warships already in production) on smaller warships and submarines, as well as training.
By October 1937, the Army had increased to around 600,000 personnel and was organised tactically under four commands, with fourteen corps and thirty-nine active divisions, including four motorised infantry and three panzer divisions (the cavalry divisions having been disbanded). There were also twenty-nine reserve divisions which could be called into service on mobilisation, and this number would steadily increase as the number of men being released from the active Army increased as they finished their compulsory service. Each corps corresponded to a Wehrkreise (which had been expanded to thirteen) just as each Reichswehr division had corresponded to one. The corps commander also functioned as the Wehrkreise commander whilst in garrison but passed that responsibility onto a deputy once he took his formation out into the field. The exception was the XIV Corps which was formed to control all the mechanised divisions dotted around Germany and had no territorial responsibility. The Wehrkreise were directly responsible to the C-in-C of the Army, while each corps would be subordinated to each of the army group commands (Heeresgruppenkommandos) when on active operations.
With the annexation of Austria and the Sudetenland, additional formations became available to the Army, with the Austrian Army providing one light, one Panzer, two infantry and two mountain divisions, while the Sudetenland was absorbed into those corresponding Wehrkreise. By March 1939, the Army totalled around 1,830,000 personnel (730,000 active, 1,100,000 reserves) with 102 divisions (fifty-one active, fifty-one reserve). A large proportion of the reserves had been diverted to form security, support and training units or administrative headquarters in the event of mobilisation but the organisation of the reserve divisions, which were all infantry divisions, mirrored that of the active force, if only short in certain equipments and certain support units.
The composition of each type of division was as follows . . .
All four panzer divisions were of a slightly different configuration. There were:
Note that the tank strengths listed above was what the division should have had – in practice there were slight variations due to production delays etc. In addition, each panzer division had a motorised artillery regiment (of two battalions), and reconnaissance, antitank, engineer and signal battalions, as well as a rear train and services. The Wehrmacht committed none of its tanks to forming battalions for close infantry support – self-propelled guns and tank destroyers were used for this, such as the Sturmgeschutz series. Armour advocates such as Heinz Guderian insisted that tanks should be concentrated into formations by themselves and given their own combat missions. These formations, Guderian argued, had the capability to punch through the enemy's main line of resistance, overcoming infantry defences with their own resources and a combination of shock and firepower. Once the line had been breached, they then had the mobility to exploit the situation, by penetrating deep into the enemy's rear or by enveloping his rear in conjunction with other panzer units. All of this was part of a broader effort to implement combined arms tactics and the panzer divisions were, in reality, a fairly balanced mix of tanks, infantry and artillery (with supporting assets) with the power of the panzer division being its ability to take advantage of the strength of all three arms, along great mobility and flexibility. One of the least appreciated strengths of the panzer division was the use of radios – Guderian had been a signals officer and realised the potential for radios to help in the coordination of fast-moving mobile formations. At the start of World War II, no other army had so successfully integrated the radio into its command structure.
The four light divisions also varied in their structure and composition:
Each division had an organic light tank battalion, a light artillery regiment (of two battalions) and supporting assets. Total strength was around 11,000 officers and men. The light divisions were an attempt to mechanise the cavalry divisions and were more controversial than the Panzer divisions, as some generals (including von Rundstedt) thought that horse cavalry would still be needed in areas that lacked the well-developed transport infrastructure of Western Europe (such as Eastern Europe and the Soviet Union). Hitler had an aversion to horses and settled the matter by adopting the French model of Dragoons with a small armoured element. These divisions were intended to operate in the traditional cavalry roles of strategic reconnaissance and flank protection.
The four motorised infantry divisions were slightly smaller than the standard infantry division by about 1,400 personnel and consisted of 3 x infantry regiments with additional combat support and combat service support units along the same lines as the standard infantry division (see below), the only difference being was that everything was transported by motor vehicle. The three mountain (Gebirgsjäger) divisions resembled the standard infantry division but again, were not organised uniformly. The 1st Mountain Division had three infantry regiments and an artillery regiment of four battalions, while the 2nd and 3rd Mountain Divisions had only two infantry regiments and an artillery regiment of three battalions. The light gun battalions were armed with a 75mm pack howitzer which could be dismantled and carried by mule, while the medium gun battalions were equipped with the 150mm howitzers of the same type used by the regular infantry. The authorised strength was 17,000 officers and men, but the 1st Mountain Division at this time had about 24,000. The thirty-five active infantry divisions consisted of three regiments, each of three infantry battalions, a cannon company and an antitank company each. Each battalion had four companies, the fourth company in each battalion being comparable to the heavy weapons company in the US Army. The division also had a mixed artillery regiment with three light and one medium battalion, equipped with 105mm and 150mm artillery pieces respectively, plus an observation battalion, as well as other support battalions such as reconnaissance, antitank, engineer and signal. The reserve infantry divisions were similarly structured although they usually varied slightly in their exact personnel strength and tended to be equipped with older support weapons.
Poland only really had two national armed services in the run up to World War II – the Army and the Navy. Air units were split between the two. The President was the nominal C-in-C but delegated the actual running of defence to the Inspector General of the Armed Forces and the Minister of War. As of early 1939, the Polish peacetime army consisted of (on paper) thirty divisions, several small mountain brigades, fourteen horse cavalry brigades, one mechanised cavalry brigade and two air divisions, with a peacetime establishment of 280,000 personnel, meaning that many units had to be kept at below establishment strength. The units were divided up between ten corps areas for administration and logistical support purposes. Army and army group commands did not exist in peacetime, instead, the Army maintained three higher commands, known as Inspectorates and commanded by senior generals at Torun (Thorn), Wilna and Lwow (Lemberg). The infantry divisions were numbered 1 through 30 and were identical in organisation, except for the 21st and 22nd Divisions, which were classed as mountain divisions and assigned to that part of Poland that bordered the Carpathian Mountains. Supporting army units were distributed throughout all ten corps areas, each of which had a medium artillery regiment and at least one tank battalion (a total of thirteen) along with antiaircraft artillery (five regiments and several separate battalions), engineers (a total of fourteen separate battalions) and signals units. By early 1939, the army could count on some 1.500.000 reservists from the classes of 1898 – 1915 (i.e. men aged between twenty-four to forty-two) being available for immediate mobilisation with another 560,000 from the classes of 1888 to 1897 (ages forty-three to fifty-two) available for selected duties if needed, such as security and support duties. The existing divisions would be brought up to full strength, fifteen additional reserve divisions created and the air units and Navy expanded.
In addition, there was a National Guard (Obrona Narodowa) consisting of men who had completed their compulsory service but were without mobilisation assignments, men who had not yet received their training for whatever reason and volunteers not yet subject to conscription. The weapons and uniforms issued to the National Guard were kept at home while their ammunition kept in the local active unit's depot. Training on a part-time basis was carried out, with units up to brigade-level able to be formed. A National Guard brigade consisted of two regiments, each of four battalions for a total strength of between 2,500 and 4,000 personnel. Eleven such brigades were formed, one in each corps area and a naval brigade at Gdynia. The active divisions consisted of three infantry regiments, an artillery regiment, a reconnaissance battalion, an antiaircraft company, a signal company as well as a rear train and services. It was planned that each infantry division would have its own engineer battalion but that was still quite a long way off by the time war broke out. Most just had engineer detachments. The infantry regiments each had three battalions (of three rifle companies and one heavy weapons company), an antitank company, a cannon platoon, a signal platoon, an engineer platoon and a small replacements and services detachment. The artillery regiment had two battalions of 75mm guns (French or Polish manufacture) and one battalion of 100mm howitzers (Czech or Polish manufacture). While an attempt was being made to replace these with 105mm and 150mm weapons of Polish manufacture, the process was far from complete. The authorised strength of an artillery regiment was 780 officers and men. The cavalry brigades consisted continued to attract some of the best officers and men and consisted of three or four cavalry regiments and one squadron each of pack artillery, signals and engineers. Each regiment (in actuality a battalion-sized formation) consisted of four line squadrons (a company-sized formation) armed with rifles, machineguns and sabres (the lance had been generally dropped in the mid-1930s), a machinegun squadron with twelve heavy machineguns, an antitank platoon with four 37mm guns and a small remount and replacement detachment.
The Germans enjoyed a substantial superiority in aircraft. Total German strength at the start of the campaign was 3,368 combat aircraft, of which about sixty-four percent was committed to the invasion of Poland. This force divided into two formations – Luftflotte (Air Fleet) 1 supporting von Bock's Army Group North and Luftflotte 4 supporting von Rundstedt's Army Group South. These included 800 medium bombers, 340 Stuka dive-bombers, 520 fighters and 250 transport aircraft. In addition to this, there were organic air units attached directly to each army group for spotting and liaison duties, with Army Group North having ninety-four and Army Group South having 168. The Germans had 2,152 aircraft arrayed against Poland, with the main aircraft types being the Heinkel He-111, Dornier Do-17, a few Junkers Ju-88, Messerschmidt Bf-109 and Bf-110 fighters, as well as Henschel Hs-126 scout planes. The two air divisions and their six associated air regiments were for administration purposes only – in wartime, the main tactical unit would be the group, of two to four squadrons, each of ten to twelve aircraft of a similar type. The Polish air forces had an approximate strength of 1,900 aircraft, but some 650 of these were trainers and 700 were older, obsolescent types. The real strength lay in some 392 frontline aircraft with 158 fighters (PZL P.11 and older P.7), 114 light bombers, thirty-six medium bombers and eighty-four observation aircraft.
The advantages enjoyed by the Wehrmacht were due to, in large part, to the much greater population and industrial capacity Germany possessed, meaning that she could spend much more defence than her smaller neighbour. Between 1935 and 1939, Germany had defence budgets that totalled $24bn, compared to Poland's $760m. This made its presence felt most keenly in the more technical of the services, the Air Force and the Navy. While Germany had an excellent industrial base for the prosecution of a war, several more years were needed to achieve a production rate high enough to maintain the output for a major prolonged conflict. The military training programme had already cut into the strength of the labour force and mobilisation would deprive it of many more thousands of technicians and workers who had completed their period of compulsory service and were assigned to reserve units. In essence then, Germany was prepared only for a war of short duration – fuel and ammunition reserves would not cover simultaneous large-scale campaigns in both the east and the west. German military planning thus had to include numerous improvisations to take account of sudden demands, a practice that was to become almost standard during World War II. Poland meanwhile, was still building up and modernising its industrial base with production of essential munitions and supplies still limited and relatively immobile, making them vulnerable to capture.
Facing Poland on the eve of war, the two army groups disposed of thirty-seven infantry divisions, one mountain (Gebirgsjäger) division, four motorised infantry (Panzer Grenadier) divisions, four light divisions, six tank (Panzer) divisions, one cavalry brigade plus a variety of border, gendarme and other paramilitary formations. Army Group North had 630,000 personnel while Army Group South totalled 886,000 personnel. The Polish Army had deployed twenty-three regular infantry divisions, three reserve infantry divisions, eight cavalry brigades and one motorised brigade, as well as some border and other paramilitary units. In terms of raw combat power, the Wehrmacht deployed some 559 infantry battalions against 376 Polish, an overall force ratio advantage of 1.5:1, or 2.3:1 along the main avenues of attack. The Wehrmacht deployed 5,805 field artillery pieces compared to 2.065 – an overall force advantage of 2.8:1 or 4.4:1 on the main avenues of attack. In terms of mechanised forces, the Wehrmacht deployed 2,511 tanks to Poland's 615, for an overall force ration of 4.1:1 or 8.2:1 on the main avenues of attack.
Army Pomorze (GenDiv W. Bortnowski)
9th Infantry Division
15th Infantry Division
27th Infantry Division
Group Wshod (BrigGen M. Boltuc)
4th Infantry Division
16th Infantry Division
Group Czersk (BrigGen Grzmot-Skotnicki)
Pomorska Cavalry Brigade
Army Modlin (BrigGen E. Krukowicz-Przedrzymirski)
8th Infantry Division
20th Infantry Division
Nowogrodzka Cavalry Brigade
Mazowiecka Cavalry Brigade
Operational Group Wyszkow (BrigGen W. Kowalski)
1st Legion Infantry Division
41st Reserve Infantry Division
Special Operational Group Narew (BrigGen C. Mlot-Fijalkowski)
18th Infantry Division
33rd Reserve Infantry Division
Podlaska Cavalry Brigade
Suwalska Cavalry Brigade
Army Poznan (GenDiv T. Kutrzeba)
14th Infantry Division
17th Wielkopolska Infantry Division
25th Infantry Division
26th infantry Division
Wielkopolska Cavalry Brigade
Podolska Cavalry Brigade
Army Lodz (GenDiv J. K. Rommel)
2nd Legion Infantry Division
10th Infantry Division
28th Infantry Division
Kresowa Cavalry Brigade
Group Piotrkow (BrigGen W. Thommee)
30th Infantry Division
Wolynska Cavalry Brigade
Army Prusy (GenDiv S. Dab-Biernacki)
13th Infantry Division
29th Infantry Division
Cavalry Operational Group (BrigGen R. Dreszer)
19th Infantry Division
Wilenska Cavalry Brigade
Skwarczynski Operational Group (BrigGen Skwarczynski)
3rd Legion Infantry Division
12th Infantry Division
36th Reserve Infantry Division
Army Krakow (BrigGen A. Szylling)
6th infantry Division
7th Infantry Division
10th Mechanised Brigade
Krakowska Cavalry Brigade
Group Slask (BrigGen J. Jagmin-Sadowski)
23rd Gornoslaska Infantry Division
55th Reserve Infantry Division
Group Bielsko (BrigGen M. Boruta-Spiechowicz)
1st Mountain Brigade
21st Mountain Infantry Division
Army Karpaty (GenDiv K. Fabrycy)
2nd Mountain Brigade
3rd Mountain Brigade
Army Group North (Generaloberst Fedor von Bock)
73rd Infantry Division
10th Light Division
206th Infantry Division
208th Infantry Division
Fourth Army (General der Artillerie Gunther von Kluge)
218th Infantry Division
Frontier Guard Command (General der Flieger Leonhard Kaupisch)
207th Infantry Division
19th Corps (General der Panzertruppen Heinz Guderian)
2nd Motorised Infantry Division
3rd Panzer Division
20th Motorised Infantry Division
2nd Corps (General der Infanterie Erich Straub)
32nd Infantry Division
3rd Infantry Division
3rd Corps (General der Artillerie Curt Haase)
50th Infantry Division
Third Army (General der Artillerie Georg von Kuchler)
217th Infantry Division
21st Corps (Generalleutnant Nikolaus von Falkenhorst)
228th Infantry Division
21st Infantry Division
1st Corps (Generalleutnant Walter Petzel)
1st Infantry Division
12th infantry Division
Corps Brand (Generalleutnant Fritz Brand)
Army Group South (GeneralOberst Gerd von Rundstedt)
239th Infantry Division
221st Infantry Division
213th infantry Division
62nd Infantry Division
68th Infantry Division
27th Infantry Division
Eighth Army (General der Infanterie Johannes Blaskowitz)
10th Corps (General der Artillerie Wilhelm Ulex)
24th infantry Division
30th Infantry Division
13th Corps (General der Cavalerie Maximilian Freiherr von Weichs)
10th Infantry Division
17th Infantry Division
Tenth Army (General der Artillerie Walter von Reichenau)
3rd Light Division
1st Light Division
11th Corps (General der Artillerie Emil Leeb)
18th Infantry Division
19th Infantry Division
16th Corps (General der Cavalerie Erich Höpner)
4th Panzer Division
1st Panzer Division
14th Infantry Division
31st Infantry Division
4th Corps (General der Infanterie Viktor von Schwedler)
46th Infantry Division
4th Infantry Division
15th Corps (General der Infanterie Hermann Hoth)
2nd Light Division
14th Corps (General der Infanterie Gustav von Wiestersheim)
13th Motorised Division
29th Motorised Division
Fourteenth Army (GeneralOberst Wilhelm List)
22nd Corps (General der Cavalerie Ewald von Kleist)
1st Mountain Division
2nd Mountain Division
8th Corps (General der Infantrie Ernst Buch)
8th infantry Division
28th Infantry Division
5th Panzer Division
17th Corps (General der Infanterie Werner Kienitz)
44th Infantry Division
45th Infantry Division
7th Infantry Division
18th Corps (General der Infanterie Baier)
2nd Panzer Division
4th Light Division
3rd Mountain Division
(Slovak) Army Group Bernolak
1st Janosik Division
2nd Skultety Division
3rd Razus Division
Mobile Group Kalinciak