Liubartas [Ljubartas] (Ukrainian: Liubart), b ?, d ca 1385. Lithuanian-Ruthenian duke of Volhynia; son of Grand Duke Gediminas. Ca 1322 he married a daughter of Prince Andrii Yuriiovych of Galicia-Volhynia. After Liubartas accepted Orthodoxy and was baptized as Dymytrii, Andrii awarded him the Lutsk land. After Andrii's death ca 1323, his successor and Liubartas's cousin, Yurii II Boleslav, granted Liubartas the Volodymyr-Volynskyi land. In 1340, after Yurii was poisoned, the boyars offered the Galician-Volhynian throne to Liubartas. Liubartas's and Yurii's brother-in-law, Casimir III the Great of Poland, contested Liubartas's rule, however. War between Poland and Liubartas and his brothers lasted for 40 years. By 1349 Casimir had seized Galicia, and by 1366 he controlled all of Volhynia except the Lutsk land. After Casimir's death in 1370, Liubartas and his brother Kęstutis failed to regain Galicia but recaptured all of Volhynia, which thereafter remained under Lithuanian-Ruthenian rule until 1569. Liubartas was succeeded briefly by his son, Fedor, who ca 1387 was forced to surrender his lands to his cousin, Vytautas the Great.