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.
Tsardom of Russia
In 1547, Ivan IV assumed the title of “Tsar and Grand Duke of all Rus'” (Царь и Великий князь всея Руси) and was crowned on 16 January, thereby turning the Grand Duchy of Moscow into Tsardom of Russia, or "the Great Russian Tsardom", as it was called in the coronation document, by Constantinople Patriarch Jeremiah II and in numerous official texts, but the state partly remained referred to as "Moscovia" () throughout Europe, predominantly in its Catholic part, though this Latin term was never used in Russia. The two names "Russia" and "Moscovia" appear to have co-existed as interchangeable during the later 16th and throughout the 17th century with different Western maps and sources using different names, so that the country was called ""Russia, or Moscovia"" () or ""Russia, popularly known as Moscovia"" (). In England of the 16th century, it was known both as Russia and Muscovy. Such notable Englishmen as Giles Fletcher, author of the book "Of the Russe Common Wealth" (1591), and Samuel Collins, author of "The Present State of Russia" (1668), both of whom visited Russia, were familiar with the term "Russia" and used it in their works. So did numerous other authors, including John Milton, who wrote "A brief history of Moscovia and of other less-known countries lying eastward of Russia", published posthumously, starting it with the words: "The Empire of Moscovia, or as others call it, Russia..."