When did the cousin of the Grand Duke of Lithuania die?
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. He was also the Prince of Hrodna (1370–1382), Prince of Lutsk (1387~1389), and the postulated king of the Hussites.
Grand Duchess Elena Pavlovna of Russia Grand Duchess Elena of Russia, Hereditary Grand Duchess of Mecklenburg (Russian: Великая Княжна Елена Павловна ) (24 December 1784 – 24 September 1803) was a daughter of Grand Duke, later Tsar Paul I of Russia and his second wife Sophie Dorothea of Württemberg. After marrying the son and heir of the Grand Duke of Mecklenburg-Schwerin she ceased to use her Russian title.