text: The First Silesian War (1740–1742, part of the War of the Austrian Succession) began on 16 December 1740 when Frederick invaded and quickly occupied almost all of Silesia within seven weeks. Though Frederick justified his occupation on dynastic grounds, the invasion of this militarily and politically vulnerable part of the Habsburg empire also had the potential to provide substantial long-term economic and strategic benefits. The occupation of Silesia added one of the most densely industrialised German regions to Frederick's kingdom and gave it control over the navigable Oder River. It nearly doubled Prussia's population and increased its territory by a third. It also prevented Augustus III, King of Poland and Elector of Saxony, from seeking to connect his own disparate lands through Silesia.
  In late March 1741, Frederick set out on campaign again to capture the few remaining fortresses within the province that were still holding out. He was surprised by the arrival of an Austrian army, which he fought at the Battle of Mollwitz on 10 April 1741. Though Frederick had served under Prince Eugene of Savoy, this was his first major battle in command of an army. Frederick's cavalry was disorganised by a charge of the Austrian horse. Believing his forces had been defeated, Frederick galloped away to avoid capture, leaving Field Marshal Kurt Schwerin to lead the disciplined Prussian infantry to victory. Frederick would later admit to humiliation at his abdication of command and would state that Mollwitz was his school. Disappointed with the performance of his cavalry, whose training his father had neglected in favour of the infantry, Frederick spent much of his time in Silesia establishing a new doctrine for them.