sentences:  Tsardom of Russia
  
  The Tsardom of Russia (, "Russkoje tsarstvo" later changed to , "Rossiyskoye tsarstvo"), also called the Tsardom of Muscovy, 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 1551 to 1700, Russia grew by 35,000 km2 per year.