Casimir II the Just

Casimir II the Just was Duke of Wiślica in Lesser Poland from 1166 to 1173, and Duke of Sandomierz from 1173 onward. In 1177, he became ruler of the Polish Seniorate Province at Kraków and thereby High Duke of Poland — a position he held until his death, though briefly interrupted by his elder brother and predecessor, Mieszko III.