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.
Secession in Russia
In Russian history, there were two periods during which significant territories fell away from it. The first is the disintegration of the Russian Empire as a result of the February and October revolutions in 1917–1921. Active disintegration processes began in the economy, social structure, public and political spheres of the Russian Empire, which ultimately led to the end of the Tsarist regime and became parts of independent states as Poland, Finland and Romania. The second is the dissolution of the Soviet Union in 1990–1991 which to the independence of the 15 republics of the USSR (Lithuania, Latvia, Estonia, Belarus, Ukraine, Georgia, Armenia, Azerbaijan, Kazakhstan, Kyrgyzstan, Uzbekistan, Turkmenistan and Tajikistan).