Sigismund I

(born Jan. 1, 1467—died April 1, 1548, Kraków, Pol.) King of Poland (1506–48). Son of Casimir IV, he became grand prince of Lithuania and king of Poland in 1506. After his army subdued the Teutonic Order in East Prussia, he established Polish suzerainty over the area, known as Ducal Prussia (1525). He added the duchy of Mazovia (now the province of Warsaw) to the Polish state in 1529. He established judicial and administrative reforms and encouraged a reform of the currency. A lover of the fine arts, he brought Italian artists to Poland and promoted the development of the Renaissance.

Source: Encyclopedia Britannica