The Province of Westphalia (German: Provinz Westfalen) was a province of the Kingdom of Prussia and the Free State of Prussia from 1815 to 1946. In turn, Prussia was the largest component state of the German Empire from 1871 to 1918, of the Weimar Republic and from 1918 to 1933, and of Nazi Germany from 1933 until 1945.
The province was formed and awarded to Prussia at the Congress of Vienna in 1815, in the aftermath of the Napoleonic Wars. It combined some territories that had previously belonged to Prussia with a range of other territories that had previously been independent principalities. The population included a large population of Catholics, a significant development for Prussia, which had hitherto been almost entirely Protestant. The politics of the province in the early nineteenth century saw local expectations of Prussian reforms, increased self-government, and a constitution largely stymied. The Revolutions of 1848 led to an effervescence of political activity in the province, but the failure of the revolution was accepted with little resistance.
