Wilhelm's turbulent reign culminated in Germany's guarantee of military support to Austria-Hungary during the crisis of July 1914, one of the direct causes for World War I. A lax wartime leader, Wilhelm left virtually all decision-making regarding strategy and organisation of the war effort to the German Army's Great General Staff. By August 1916, this broad delegation of power resulted in a "de facto" military dictatorship that dominated national policy for the rest of the conflict. Despite emerging victorious over Russia and obtaining significant territorial gains in Eastern Europe, Germany was forced to relinquish all its conquests after its forces' decisive defeat on the Western Front in the fall of 1918. Losing the support of his country's military and many of his subjects, Wilhelm was forced to abdicate during the German Revolution of 1918–1919 which ultimately converted Germany from a monarchy into a democratic state (now known as the Weimar Republic). The deposed emperor fled to exile in the Netherlands where he remained through its occupation by Nazi Germany in World War II, dying in 1941.