Nutvilas Kęstutaitis
Tautvilas or Towtwil (circa 1352-1355- September 1390) was one of the sons of Kęstutis, Grand Duke of Lithuania, and a strong supporter of Vitautas the Great in his struggles against his cousin Jogaila.
In 1380, Jogaila secretly signed the Treaty of Dovydiškės with the Teutonic Knights against Kęstutis. This led to the outbreak of a civil war. Kęstutis and his son Vitautas were captured and imprisoned in Kreva Castle. In 1382 Kęstutis died in strange circumstances, while Vitautas managed to escape and sought allies among the Teutonic Knights. Around the same time Jogaila banished to Tautvilas of Navahrudak, city that he and his brother Vaidotas were governing. Tautvilas then joined the struggle of his brother Vitautas. While visiting the Teutonic Knights, he was baptized as Kondrat on October 21, 1383. In 1384 Vitautas and Jogaila were reconciled and the civil war ended.
When Jogaila signed the union of Krewo and became king of Poland, left as its regent in Lithuania his unpopular brother Skirgaila. Vitautas saw the opportunity to gain power and began the Lithuanian Civil War (1389-92). His first military campaign against Vilna was unsuccessful and he had to ask for help to the Teutonic Order for the second time. Tautvilas was with him again. The joint forces of Vitautas and the Knights attacked Vilna in September 1390. According to the chronicles of Wigand of Marburg, Tautvilas died in the battle for Vilna Castle.
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