Casimir III the Great (April 30, 1310 – November 5, 1370) who reigns from 1333 to 1370, is the last King of Poland from the Piast dynasty, and the son of King Wladyslaw I ("the Elbow-high") and Duchess Hedwig of Kalisz.

Born in Kowal, Casimir first marries Anna, or Aldona Ona, the daughter of Grand Duke Gediminas of Lithuania.

The marriage produces two daughters, Cunigunde (d. 1357), whois married to Louis VI the Roman, the son of Louis IV, Holy Roman Emperor, and Elisabeth, who is married to Duke Bogislaus V of Pomerania.

Aldona dies in 1339, and Casimir then marries Adelaide of Hesse.

He divorces Adelaide in 1356, marries Christina, divorces her, and while Adelaide and possibly Christina are still alive (ca.

1365), he marries Hedwig of Głogów and Sagan.

He has three daughters by his fourth wife, and they are still very young when he dies in 1370 from an injury received while hunting, and regarded as of dubious legitimacy because of Casimir's bigamy.

His nephew, King Louis I of Hungary, succeeds him to become king of Poland in personal union with Hungary.