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.
Russia–Turkey relations
The Turks in Anatolia were separated from Russia by the Black Sea and the Polish-Lithuanian Commonwealth to the northwest and the Caucasus mountains to the east. The Turks founded the Ottoman Empire in Anatolia and began expanding outwards, while Russia was doing the same. The two empires began a series of clashes over the Black Sea basin.