Sigismund I the Old

Born in Kozienice in 1467, Sigismund was the fifth of thirteen children and watched three older brothers take thrones before him: Vladislaus claimed Bohemia and Hungary, John Albert got Poland, Alexander took Lithuania and then both after John's sudden death in 1501. Only in 1506, at 39, did Sigismund finally inherit the double crown. He spent the next four decades shoring up borders - his forces beat Moldavia at Obertyn in 1531 and Muscovy in 1535 - and reshaping the realm itself: he forced his nephew Albert of Prussia into feudal homage, annexed Mazovia and Warsaw, and let his second wife Bona Sforza flood the court with Italian architects, cooks, and fashions that defined the Polish Renaissance. He made his only surviving son, Sigismund Augustus, co-king in 1529 and died in 1548 after the longest reign of his dynasty.