The Thirteen Years' War was a conflict fought in 1454–1466 between the Prussian Confederation, allied with the Crown of the Kingdom of Poland, and the State of the Teutonic Order. The war began as an uprising by Prussian cities and local nobility to win independence from the Teutonic Knights. In 1454 Casimir IV married Elisabeth of Habsburg and the Prussian Confederation asked Poland's King Casimir IV Jagiellon for help and offered to accept the king as protector instead of the Teutonic Order. When the King assented, war broke out between supporters of the Prussian Confederation, backed by Poland, and backers of government by the Teutonic Knights. The Thirteen Years' War ended in the victory of the Prussian Confederation and Poland and in the Second Peace of Thorn (1466). This was soon followed by the War of the Priests (1467–1479), a drawn-out dispute over the independence of the Prussian Prince-Bishopric of Warmia (Ermland), in which the Knights also sought revision of the Peace of Thorn.