When was the  sixteenth century King of Poland and Grand Duke of Lithuania died?
Sigismund II Augustus Sigismund II Augustus (Polish: "Zygmunt II August" , Ruthenian: "Żygimont II Awgust", Lithuanian: "Žygimantas II Augustas" , German: "Sigismund II. August" ) (1 August 1520 – 7 July 1572) was the King of Poland and Grand Duke of Lithuania, the only son of Sigismund I the Old, whom Sigismund II succeeded in 1548. Married three times, the last of the Jagiellons remained childless, and through the Union of Lublin introduced a free elective monarchy.
Magnus, Duke of Holstein Magnus of Holstein (5 September [O.S. 26 August] 1540 – 28 March [O.S. 18 March] 1583 ) was a Prince of Denmark and a member of the House of Oldenburg. As a vassal of Ivan IV of Russia, he was the titular King of Livonia from 1570 to 1578.