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.
Albert Frederick, Duke of Prussia Albert Frederick (German: "Albrecht Friedrich" , Polish: "Albrecht Fryderyk" ; 7 May 1553, in Königsberg – 28 August 1618, in Fischhausen, Rybaki) was Duke of Prussia from 1568 until his death. He was a son of Albert of Prussia and Anna Marie of Brunswick-Lüneburg. He was the second and last Prussian duke of the Ansbach branch of the Hohenzollern family.