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.
Military history of the Russian Empire
In the resultant Treaty of Nystad, Peter was extremely lenient with the Swedes, keeping Estonia, Livonia, Ingria, and part of southern Finland (especially Saint Petersburg) in exchange for the return of most of Finland to the Swedes and the payment of 2 million silver riksdaler. Peter could afford to be lenient, as the war was a decisive shift in the European balance of power. The Swedish Empire was carved up, and its position as a great power was taken by Russia. Celebrating these victories, Peter took the title of "imperator", and the Russian Empire was thus founded. The Northern War left Russia as the dominant power in Northern Europe, and gave it firm control over the Baltic and thus a "window to the west". The war had also bettered Russia's position with respect to its Polish rival, which came to a head much later under Catherine the Great with the First Partition of Poland. Finally, it put Russia into direct contact with another of the great powers of Europe, Germany. Peter himself emerged a national hero; scripts at the time compared him to Hercules, Sampson, and David.