The XIX Army Corps was formed on 1 July 1939 in Vienna to group together the 2nd Panzer Division and the 4th Light Division, the latter of which became 9th Panzer Division on 3 January 1940. At its inception, the unit was not part of any particular Wehrkreis. The initial commander of XIX Army Corps was General der Panzertruppe (then equivalent to the rank of lieutenant general in the English-speaking world) Heinz Guderian. Guderian had previously made a name for himself as a supporter of a motorized style of warfare using armored vehicles and air support, a style that is often dubbed "Blitzkrieg" ('lightning warfare') in the English-speaking world, although German military officers like Guderian did not themselves use that term. He also had previous experience as a panzer leader in the context of bloodless invasion, as he was involved in guiding German panzer forces, specifically 2nd Panzer Division, through the Anschluss of Austria in March 1938. This was in spite of the fact that he had already officially been replaced as commander of that unit by Rudolf Veiel and was only ordered back to that post by Ludwig Beck for the purpose of the Anschluss. During that action, Guderian reported that more than 30% (70% according to Alfred Jodl) of German panzer forces malfunctioned.