Tsardom of Russia
The Tsardom of Russia, also known as the Tsardom of Moscow, was the centralized Russian state from the assumption of the title of tsar by Ivan IV in 1547 until the foundation of the Russian Empire by Peter the Great in 1721. From 1550 to 1700, Russia grew by an average of 35,000 square kilometres (14,000 sq mi) per year.