Following the defeat of Imperial Germany in the First World War and the foundation of the Weimar Republic a new military force was needed (apart from the independent volunteer Freikorps units) and the Vorläufige Reichswehr (Provisional Army) was formed on 6 March 1919 from the remains of the old Imperial forces.

The Vorläufige Reichswehr was made up of 43 brigades, this went down to 20 brigades when it was restructured into the Übergangsheer (Transitional Army) on 1 October 1919. In May 1920 it was downsized to 200.000 men and restructured again, forming three Cavalry Divisions and seven Infantry Divisions. On 1 October 1920 the brigades were replaced by regiments and the manpower was now only 100.000 men as stipulated by the Versailles Treaty. The name of the army was changed once again on 1 January 1921, this time to Reichsheer (National Army), a name it would keep until 20 May 1935 when it was replaced by the Heer.

The Reichswehr included the Reichsheer (as described above) and the Reichsmarine (National Navy) and was replaced by the Wehrmacht on 20 May 1935.