When did the cousin of the Grand Duke of Lithuania die?
Lithuanian Civil War (1389–92): The Lithuanian Civil War of 1389–92 was the second civil conflict between Jogaila, King of Poland and Grand Duke of Lithuania, and his cousin Vytautas. Vytautas: Vytautas (c. 1350 – October 27, 1430), also known as Vytautas the Great (Lithuanian: "   ", Belarusian: "Вітаўт Кейстутавіч (Vitaŭt Kiejstutavič)" , Polish: "Witold Kiejstutowicz" , Rusyn: "Vitovt", Latin: "Alexander Vitoldus") from the 15th century onwards, was a ruler of the Grand Duchy of Lithuania, which chiefly encompassed the Lithuanians and Ruthenians.
October 27, 1430