Bolesław Jerzy II of Mazovia (born 1308)

Yuri II Boleslav, was King of Ruthenia and Dominus of the Galicia–Volhynian lands (1325–1340). A foreigner and a Catholic by birth, he was the son of Trojden I, Duke of Masovia and a member of the Polish Piast dynasty. Highly unpopular in Orthodox Ruthenia, his murder prompted a war of succession, known as the Galicia–Volhynia Wars.