Heinz Guderian first proposed the formation of panzer units larger than a regiment, but the inspector of motorized troops, Otto von Stuelpnagel, rejected the proposal.[2] After his replacement by Oswald Lutz, Guderian's mentor, the idea gained more support in the Wehrmacht, and after 1933 was also supported by Adolf Hitler. The first three panzer divisions were formed on 15 October 1935.[3] The 1st Panzerdivision was formed in Weimar and commanded by Maximilian von Weichs, the 2nd Panzerdivision was formed in Würzburg and commanded by Guderian, and the 3rd Panzerdivision was formed in Berlin and commanded by Ernst Feßmann.