From his predecessor, Frederick inherited the Livonian War. In 1560, he installed his younger brother, Magnus of Holstein (1540–1583), in the Bishopric of Ösel–Wiek. King Frederick II largely tried to avoid conflict in Livonia and consolidated amicable relations with Tsar Ivan IV of Russia in the 1562 Treaty of Mozhaysk. His brother Magnus was later made titular King of Livonia, as a vassal of Tsar Ivan IV.