Casimir III the Great (Polish: Kazimierz III Wielki; 30 April 1310 – 5 November 1370) reigned as the King of Poland from 1333 to 1370.
He was the third son of King Wladyslaw I ("the Elbow-high") and Duchess Jadwiga of Kalisz, and the last Polish king from the Piast dynasty.Kazimierz inherited a kingdom weakened by war and made it prosperous and wealthy.
He reformed the Polish army and doubled the size of the kingdom.
He reformed the judicial system and introduced a legal code, gaining the title "the Polish Justinian".
Kazimierz built extensively and founded the University of Kraków, the oldest Polish university.
He also confirmed privileges and protections previously granted to Jews and encouraged them to settle in Poland in great numbers.
Kazimierz left no lawful male heir to his throne, producing only daughters.
When Kazimierz died in 1370 from an injury received while hunting, his nephew, King Louis I of Hungary, succeeded him as king of Poland in personal union with Hungary.