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. At issue was control of the Grand Duchy of Lithuania, then the largest state in Europe. Jogaila had been crowned King of Poland in 1386; he installed his brother Skirgaila as ruler of Lithuania. Skirgaila proved unpopular and Vytautas attempted to depose him. When his first attempt to take the capital city of Vilnius failed, Vytautas forged an alliance with the Teutonic Knights, their common enemy – just as both cousins had done during the Lithuanian Civil War between 1381 and 1384. Vytautas and the Knights unsuccessfully besieged Vilnius in 1390. Over the next two years it became clear that neither side could achieve a quick victory, and Jogaila proposed a compromise: Vytautas would become Grand Duke and Jogaila would remain Superior Duke. This proposal was formalized in the Ostrów Agreement of 1392, and Vytautas turned against the Knights. He went on to reign as Grand Duke of Lithuania for 38 years, and the cousins remained at peace.
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.