Union of Krewo

After the death of Louis I, king of Hungary and Poland, in 1382 the Polish lords crowned his younger daughter Jadwiga ‘king’ of Poland in October 1384 and sought a husband who would not tie Poland to Hungary or Austria; nobles of Lesser Poland proposed Jogaila, the pagan grand duke of Lithuania. Jogaila, whose state comprised pagan Lithuanians and Orthodox Ruthenians, knew that conversion was inevitable but wished to avoid dependence on the Teutonic Order; in 1384 he had also considered becoming Orthodox and marrying a daughter of Dmitry Donskoy.

In mid-1385 a Lithuanian embassy led by Jogaila's brother Skirgaila negotiated in Kraków and with Jadwiga's mother Elizabeth in Buda, and Polish envoys came to Lithuania. At Krewo Jogaila confirmed in writing that in return for the marriage he would be baptized in the Catholic faith together with his brothers, nobles and people, pay 200,000 florins to William of Austria, to whom Jadwiga had been betrothed, recover the lands Poland had lost, free Polish captives and ‘attach’ (applicare) his Lithuanian and Ruthenian lands to the Crown of Poland; his brothers and his cousin Vytautas added their seals. What applicare meant — incorporation or a looser bond — has been debated ever since. The document, found only in 1835 in the archive of the Kraków cathedral chapter, is mentioned in no source of the time, yet doubts about its authenticity have found little support.

Jogaila was baptized Władysław in Kraków on 15 February 1386, married Jadwiga three days later and was crowned king of Poland on 4 March. In 1387, back in Lithuania, he had the people of Vilnius and its region baptized, decided to build a cathedral in Vilnius and to ask the pope for a bishopric, and granted privileges to nobles who accepted the Catholic faith: more than a century after the short-lived conversion of Mindaugas, Lithuania became Christian for good. The Orthodox nobility resented the growing Polish influence, and after a civil war Vytautas became grand duke in 1392 under Jogaila's overlordship; the union was renegotiated several times until the Union of Lublin in 1569 created the Polish–Lithuanian Commonwealth. Krewo castle had seen an earlier drama: there, in August 1382, Jogaila's uncle and rival Kęstutis had died in captivity, reportedly strangled.