Complex sentence: The final Soviet name for the republic, the Russian Soviet Federative Socialist Republic, was adopted in the Soviet Constitution of 1936--by that time, Soviet Russia gained roughly the same borders of the old Tsardom of Russia before the Great Northern War of 1700.
Split into simpler sentences: The final Soviet name for the republic, the Russian Soviet Federative Socialist Republic, was adopted in the Soviet Constitution of 1936. By that time, Soviet Russia had gained roughly the same borders of the old Tsardom of Russia before the Great Northern War of 1700.