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.
Janusz Radziwiłł (1612–1655) Prince Janusz Radziwiłł, also known as Janusz the Second or Janusz the Younger (Lithuanian: "Jonušas Radvila" , 2 December 1612 – 31 December 1655) was a noble and magnate in the Polish–Lithuanian Commonwealth. Throughout his life he occupied a number of posts in the state administration, including that of Court Chamberlain of Lithuania (from 1633), Field Hetman of Lithuania (from 1646) and Grand Hetman of Lithuania (from 1654). He was also a voivode of Vilna Voivodeship (from 1653), as well as a starost of Samogitia, Kamieniec, Kazimierz and Sejwy. He was a protector of the Protestant religion in Lithuania and sponsor of many Protestant schools and churches.