REGIS : POLONIE, Crown within a circle / MK MONETA KAZIMIRI Polish heraldic eagle (known as "White Eagle"). 20mm, 0.98 grams. Krakow mint. Kopicki 380.
Casimir succeeded his brother as King of Poland after a three-year interregnum on 25 June 1447. In 1454, he married Elisabeth of Austria, daughter of the late King of the Romans Albert II of Habsburg by his late wife Elisabeth II of Bohemia. Her distant relative Frederick of Habsburg became Holy Roman Emperor and reigned as Frederick III until after Casimir's own death. The marriage strengthened the ties between the house of Jagiellon and the sovereigns of Hungary-Bohemia and put Casimir at odds with the Holy Roman Emperor through internal Habsburg rivalry. That same year, Casimir was approached by the Prussian Confederation for aid against the Teutonic Order, which he promised, by the act of incorporation of Prussia to the Polish Kingdom. However, when the cities of Prussia rebelled against the Teutons, the Order resisted with greater strength than expected, and the Thirteen Years' War (1454-1466) ensued. Casimir and the Prussian Confederation defeated the Teutonic Order, taking over its capital at Marienburg (Malbork Castle). In the Peace of Torun (1466), the Order recognized Polish sovereignty over Royal Prussia and the Polish crown's overlordship over Ducal Prussia. Elisabeth's only brother Ladislas, king of Bohemia and Hungary, died in 1457, and after that Casimir and Elisabeth's dynastic interests were directed also towards her brother's former kingdoms.