The Holy Roman Empire, of which Vienna became the capital with Emperor Maximilian I (1508-1519), Emperor Charles V (1519-1556) and Emperor Ferdinand I (1556-1564), was often a theatre of war during this period and was consistently involved in military conflicts over power, confessions, land, and people. The collections of the Museum of Military History begin at a time when military history is undergoing a transformation from the Volksaufgebot (people's volunteer corps) to the standing army. The Imperial armies, which up to the Thirty Years' War were inconsistently equipped and enlisted only for the period of a campaign, were now transformed into a salaried, "standing" army.