The German Army (German: Heer,) was the land forces component of the Wehrmacht, the regular Armed Forces of Nazi Germany, from 1935 until it effectively ceased to exist in 1945 and then was formally dissolved in August 1946. During World War II, a total of about 13.6 million soldiers served in the German Army. Army personnel were made up of volunteers and conscripts.
Only 17 months after Adolf Hitler announced the German rearmament program in 1935, the army reached its projected goal of 36 divisions. During the autumn of 1937, two more corps were formed. In 1938 four additional corps were formed with the inclusion of the five divisions of the Austrian Army after the Anschluss in March. During the period of its expansion under Hitler, the German Army continued to develop concepts pioneered during World War I, combining ground and air assets into combined arms forces. Coupled with operational and tactical methods such as encirclements and "battle of annihilation", the German military managed quick victories in the two initial years of World War II, a new style of warfare described as Blitzkrieg (lightning war) for its speed and destructive power.
(More on Wiki HERE)