Casimir the Great found Poland built of wood and left it stone
Polish schoolchildren still recite a rhyme about Casimir III: he inherited a country of wooden towns and left it walled in brick and stone. During his reign from 1333 to 1370, nearly 30 towns gained fortifications and about 50 castles rose, yet he preferred treaties to battles whenever he could.
Casimir was born in 1310 in Kowal, a son of Władysław the Short, who had reunited much of Poland and been crowned in 1320. When his father died in March 1333, Casimir inherited a small, war-ravaged realm of two provinces, surrounded by rivals. John of Bohemia still claimed the Polish crown, and the Teutonic Order held Polish territory. Casimir was crowned at Wawel Cathedral that April alongside his Lithuanian wife, Aldona.
Rather than fight on every front, he negotiated. In 1335 the Bohemian royal family agreed to drop their claim to the Polish title in return for his promise to respect their holdings in Silesia and Mazovia. An arbitration court at Visegrád that November, bringing together the kings of Poland, Bohemia and Hungary in person for the first time, restored Kuyavia and the Dobrzyń Land to Poland, though Casimir had to give up Pomerania. He accepted the loss of Silesia but expanded eastward by annexing Red Ruthenia, and he took the title King of Ruthenia in 1340.
At home he codified law in statutes issued at Wiślica in 1347 and at Piotrków, earning the nickname the Polish Justinian. He created the idea of the Crown of the Polish Kingdom, a state that existed apart from whoever ruled it, rather than as dynastic property. Towns flourished under Magdeburg law, and he extended protections for Jewish communities and encouraged Jews to settle in large numbers. Quarantines during the Black Death limited its toll, with grain production barely disrupted.
In 1364 he founded the University of Kraków, only the second in Central Europe after Prague, and hosted a gathering of kings to display Poland's wealth. He is the only Polish ruler to receive and keep the epithet Great. Without a legitimate son, he was the last Piast king; at his death in 1370 the crown passed to his nephew, Louis I of Hungary.
Source: Casimir III the Great
