Casimir IV the Jagiellonian (Polish: Kazimierz Jagiellończyk, Lithuanian Kazimieras Jogailaitis) (1427 - 1492), of the House of Jagiello was grand duke of Lithuania from 1440 and king of Poland from 1447 until his death.

The son of king Wladislaus II Jagiełło and younger brother to Wladislaus III, Casimir succeeded the latter after a three-year interregnum. He married in 1454 Elisabeth, the daughter of Albert II of Habsburg. The marriage strengthened the ties between the houses of Jagiello and Habsburg.

That same year, Casimir was approached by the Prussians for aid against the ruling Teutonic Order, which he promised, by the act of incorporation of Prussia to Polish Kingdom; however, when the cities of Prussia rebelled against Teutons, the order resisted with the stronger power then expected, resulting in Thirteen Years' War (1454-1466). Casimir, in alliance with the Prussian Confederation, defeated the Teutonic Order taking over its capital in Malbork, which in the ensuing Second Treaty of Thorn recognised Polish sovereignty over Royal Prussia and the Polish crown's overlordship over Ducal Prussia.

A daughter, Jadwiga, was married to George the Rich Wittelsbach of Bavaria. Delegates had gone to Kraków to negotiate the marriage. Their so-called Landshut Wedding took place in Bavaria with much pomp and celebration in 1475.

His son named Casimir was to have been married to the daughter of emperor Frederick III but he instead chose a religious life, eventually becoming canonized as St. Casimir and his son Hungary and Bohemia.

External links

• Pages and Forums on the Lithuanian History (http://www.istorija.net/)