In the summer of 1941, Romania joined Hitler's Axis in the invasion of the Soviet Union, recovering Bessarabia and Northern Bukovina, as well as occupying the territory to the east of the Dniester it dubbed "Transnistria". Soviet partisans continued to be active in both regions. By the end of World War II, the Soviet Union had reconquered all of the lost territories, reestablishing Soviet authority there.