 In 1547, the Grand Duchy of Moscow officially became known as the Tsardom of Russia, with Ivan IV crowned as Tsar and "Ruler of all Rus'".The tsar sought to gather the ethnically Ruthenian lands of the former Kievan Rus', engaging with other powers around the Baltic Sea in the Livonian War.During the reign of Sigismund II Augustus in Poland and Lithuania, Tsar Ivan IV invaded Livonia, first in 1568 when the Livonian Knights sought alliance with Poland and Lithuania; the Poles and Lithuanians were able to defend only southern Livonia.