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.
Prince Feodor Alexandrovich of Russia Prince Feodor Alexandrovich of Russia (23 December 1898 – 30 November 1968) was the second son and third child of Grand Duke Alexander Mikhailovich of Russia and Grand Duchess Xenia Alexandrovna of Russia. He was also a nephew of Nicholas II of Russia, the last Tsar.