The Marriage of Poland and Lithuania

In 1385, Lithuania was a very large territory on Poland's eastern border. Poland's throne was held by the pre-teen Jadwiga, who was supposed to marry William of Austria, then Siemovit of Poland, and finally the 30-year-old Jogaila, Grand Duke of Lithuania. An arrangement like this takes a lot of planning and legal wrangling. In the case of Jadwiga and Jogaila, that legal wrangling was embodied in the Union of Krewo, whose document is seen here.

The prenuptial arrangements in the Union of Krewo (called so because it was signed at Krevo Castle) included a certain sine qua non: Jogaila had to convert to Christianity. Poland was a Christian country; Lithuania was exposed to Eastern Orthodoxy on its eastern border with Russian people, but still embraced polytheism. Jogaila was defending Lithuania from Teutonic Knights, who kept attacking under the pretense of a Crusade. He understood that becoming Christian would create an alliance with other countries and pull the rug out from under the Teutonic Order.

The other promises of the document:

• Conversion of Jogaila, Lithuanian nobles and all pagan Lithuanians to Roman Catholicism
• Paying 200,000 florins to William of Austria for terminating his engagement with Jadwiga
• Returning all lands lost in previous Lithuanian-Polish wars
• Release of all war prisoners of Poland (c.45,000) held by the Lithuanians
• Attaching Lithuanian lands to the Crown of Poland

In light of these promises, Poland agreed that Jogaila could be their king. In February 1386 Jogaila was baptized by Archbishop Bodzanta. As his baptismal name, he chose Wladislaus in honor of Jadwiga's great-grandfather king Władysław I the Elbow-high.

There was a problem with William of Austria, to whom Jadwiga had been promised nearly since birth. William claimed she was officially married to him, and the marriage to Jogaila made her a bigamist. His protests carried weight with Pope Urban VI, who would not confirm the marriage of Jadwiga and Jogaila. It took a few years until Pope Boniface IX (1389-1404) confirmed their marriage. (Boniface had also similarly supported a certain English arrangement that had raised eyebrows.)

Although this union was the start of four centuries of Lithuania-Poland shared history, Lithuania did not appreciate increasing Polish influence, and Jogaila's brother Skirgaila, who had been left behind to rule Lithuania, was unpopular. This gave Jogaila's cousin Vytautas the opportunity to try to gain more power, leading to a Lithuanian Civil War (1389-92), but that was resolved by making Vytautas Grand Duke while leaving Jogaila as his overlord.

Another complication came from an unexpected source: Jadwiga's sister, Mary, whose husband had become King of Hungary and had his own ideas of what should happen to Poland. I'll go into that next time.