History of Russia
The war ended in 1721 when an exhausted Sweden sued for peace with Russia. Peter acquired four provinces situated south and east of the Gulf of Finland, thus securing his coveted access to the sea. There, in 1703, he had already founded the city that was to become Russia's new capital, Saint Petersburg, as a "window opened upon Europe" to replace Moscow, long Russia's cultural center. Russian intervention in the Commonwealth marked, with the Silent Sejm, the beginning of a 200-year domination of that region by the Russian Empire. In celebration of his conquests, Peter assumed the title of emperor, and the Russian Tsardom officially became the Russian Empire in 1721.
History of the administrative division of Russia
Technically, the territorial-administrative reform started out in the Tsardom of Russia before the Imperial period. On , 1708, in order to improve the manageability of the vast territory of the state, Tsar Peter the Great issued an ukase (edict) dividing Russia into eight administrative divisions, called governorates ("guberniyas"), which replaced the 166 uyezds and razryads which existed before the reform: