Russian Empire
Though the Empire was only officially proclaimed by Tsar Peter I following the Treaty of Nystad (1721), some historians would argue that it was truly born either when Ivan III of Russia conquered Veliky Novgorod in 1478, or when Ivan the Terrible conquered the Khanate of Kazan in 1552. According to another point of view, the term "Tsardom", which was used after the coronation of Ivan IV in 1547, was already a contemporary Russian word for empire.
Russian Empire
Peter's first military efforts were directed against the Ottoman Turks. His attention then turned to the North. Peter still lacked a secure northern seaport, except at Archangel on the White Sea, where the harbor was frozen for nine months a year. Access to the Baltic was blocked by Sweden, whose territory enclosed it on three sides. Peter's ambitions for a "window to the sea" led him to make a secret alliance in 1699 with Saxony, the Polish–Lithuanian Commonwealth and Denmark against Sweden, resulting in the Great Northern War. The war ended in 1721 when an exhausted Sweden asked for peace with Russia. Peter acquired four provinces situated south and east of the Gulf of Finland. The coveted access to the sea was now secured. There he built Russia's new capital, Saint Petersburg, to replace Moscow, which had long been Russia's cultural center. In 1722, he turned his aspirations as first Russian monarch toward increasing Russian influence in the Caucasus and the Caspian Sea at the expense of the weakened Safavid Persians. He made Astrakhan the centre of military efforts against Persia, and waged the first full-scale war against them in 1722–23.