After the Nazi seizure of power in 1933, one of Adolf Hitler's most overt and audacious moves was to establish the Wehrmacht, a modern armed force fully capable of offensive use. Fulfilling the Nazi regime's long-term goals of regaining lost territory and dominating its neighbours required the reinstatement of conscription and massive investment and spending on the armaments industry. In December 1941, Hitler designated himself as commander-in-chief of the Wehrmacht.
The Wehrmacht formed the heart of Germany's politico-military power. In the early part of World War II, Hitler's generals employed the Wehrmacht through innovative combined arms tactics (close cover air-support, mechanized armor, and infantry) to devastating effect in what was called a Blitzkrieg (lightning war). The Wehrmacht's new military structure, unique combat techniques, newly developed weapons, and unprecedented speed and brutality crushed their opponents.
Closely cooperating with the SS (especially on the Eastern Front), the German armed forces committed numerous war crimes and atrocities, despite later denials. By the time the war ended in Europe in May 1945, the Wehrmacht had lost approximately 11,300,000 men, about half of whom were missing or killed during the war. Only a few of the Wehrmacht's upper leadership were tried for war crimes, despite evidence suggesting that more were involved in illegal actions.
The German term Wehrmacht generically describes any nation's armed forces; for example, Britische Wehrmacht means "British Armed Forces." The Frankfurt Constitution of 1848 designated all German military forces as the "German Wehrmacht", consisting of the Seemacht (sea force) and the Landmacht (land force). In 1919, the term Wehrmacht also appears in Article 47 of the Weimar Constitution, establishing that: "The Reich's President holds supreme command of all armed forces of the Reich". From 1919, Germany's national defense force was known as the Reichswehr, a name that was dropped in favor of Wehrmacht on 21 May 1935.
In January 1919, after World War I ended with the signing of the armistice of 11 November 1918, the armed forces were dubbed Friedensheer (peace army). In March 1919, the national assembly passed a law founding a 420,000-strong preliminary army, the Vorläufige Reichswehr. The terms of the Treaty of Versailles were announced in May, and in June, Germany signed the treaty that, among other terms, imposed severe constraints on the size of Germany's armed forces. The army was limited to one hundred thousand men with an additional fifteen thousand in the navy. The fleet was to consist of at most six battleships, six cruisers, and twelve destroyers. Submarines, tanks and heavy artillery were forbidden and the air-force was dissolved. A new post-war military, the Reichswehr, was established on 23 March 1921. General conscription was abolished under another mandate of the Versailles treaty.