According to the chronicles of Wigand of Marburg, he was the commander of the garrison of the newly built Kaunas Castle during a three-week-long siege in April 1362. After strong resistance the castle was taken over and then destroyed. Vaidotas with 36 men tried to break through, but was taken prisoner. The defeat was one of the largest and important military victories of the Teutonic Knights in the 14th century against Lithuania.
Because of very limited historical sources, Vaidotas is sometimes confused with Vaidutis (Waydutte), son of Butautas and grandson of Kęstutis. Some historians also argue that Butautas and Vaidotas were the same person and their names are different because of a different dialect. Further confusion is introduced by Bychowiec Chronicle, an unreliable chronicle from the 16th century, which claims that Vaidotas died in his youth in Lithuania.
^(Lithuanian)Vytautas Spečiūnas, ed. (2004). "Vaidotas". Lietuvos valdovai (XIII-XVIII a.): enciklopedinis žinynas. Vilnius: Mokslo ir enciklopedijų leidybos institutas. p. 76. ISBN5-420-01535-8.
^Rowell, S. C. (1994). Lithuania Ascending: A Pagan Empire Within East-Central Europe, 1295–1345. Cambridge Studies in Medieval Life and Thought: Fourth Series. Cambridge University Press. xxxiii. ISBN978-0-521-45011-9.