Casimir III the Great

Casimir III, King of Poland from 1333 to 1370, took over a small, war-damaged kingdom and left it larger, better defended and governed by written law. The last king of the Piast dynasty, he preferred treaties to battles in the west, expanded into Ruthenia in the east, founded the university at Kraków and welcomed Jewish settlers. He is the only Polish ruler whose epithet "the Great" has stuck.

Casimir was born on 30 April 1310 at Kowal in Kuyavia, son of Władysław I the Short, who reunited much of Poland and was crowned in 1320. In 1325 Casimir married Aldona, daughter of the Lithuanian grand duke Gediminas, to cement an alliance against the Teutonic Order. His father's wars with Bohemia and the Order went badly: the Knights took Kuyavia, and King John of Bohemia, who still called himself King of Poland, won the allegiance of most Silesian dukes. When Władysław died on 2 March 1333, Casimir inherited essentially two provinces, Greater and Lesser Poland. He was crowned at Wawel Cathedral on 25 April.

Casimir set out to neutralise his enemies one by one. In 1335 John of Bohemia agreed to drop his Polish title in exchange for Casimir's promise not to contest Bohemian rule in Silesia. At Visegrád that November, with the kings of Bohemia and Hungary as arbiters, the Teutonic Order was told to return Kuyavia and the Dobrzyń Land, while Casimir gave up Pomerania and the Chełmno Land. Accepting these losses freed him to turn east, where he conquered the Ruthenian lands of the former Galicia–Volhynia, known in Poland as Red Ruthenia, and took the title King of Ruthenia from 1340. The new territory opened routes to the Black Sea trade.

Casimir gave Poland a body of written law. Statutes issued at Wiślica in 1347, together with those for Greater Poland, codified civil and criminal law and earned him the nickname "the Polish Justinian". He promoted the idea of the Crown of the Kingdom of Poland as a state existing apart from the person of the king. Towns grew under German town law, and his building programme gave nearly 30 towns stone walls and added some 50 castles, giving rise to the saying that he found Poland wooden and left it built of stone.

With the pope's permission Casimir founded the University of Kraków in 1364, the second university in Central Europe after Prague. That year he also hosted a congress of monarchs in Kraków. In 1334 he confirmed the charter of privileges granted to Jews in 1264, punishing the forced baptism of Jewish children and the desecration of Jewish cemeteries, and he encouraged Jews to settle in Poland in large numbers. Stories of a Jewish mistress named Esterka are legend rather than documented fact. Popular tradition also called him "the Peasants' King" for protecting commoners against powerful lords.

Casimir married four times, and his second divorce and later marriages were disputed as bigamous. He had daughters but no legitimate son. In 1355 he named his nephew, King Louis I of Hungary, as heir in return for Hungarian support. His will tried to favour his grandson Casimir of Pomerania, but Louis overturned it. Casimir died in Kraków on 5 November 1370, ending Piast rule; the crown passed to Louis, and later to Louis's daughter Jadwiga.

Our 1300 map shows the fragmented Poland shortly before Casimir's birth, hemmed in by the Teutonic Order's state, and our 1400 map shows the kingdom after his eastern expansion into Ruthenia.