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.
Michael of Russia
Michael I of Russia (Russian: Михаи́л Фёдорович Рома́нов, "Mikhail Fyodorovich Romanov") () became the first Russian Tsar of the House of Romanov after the zemskiy sobor of 1613 elected him to rule the Tsardom of Russia. He was the son of Feodor Nikitich Romanov (later known as Patriarch Filaret) and of Xenia (later known as "the "great nun"" Martha). He was also a nephew of Feodor I (the last Rurikid Tsar) through his great-aunt Anastasia Romanovna (his paternal grandfather's sister) and through marriage with Tsar Ivan IV of Russia. His accession marked the end of the Time of Troubles. During his reign, Russia conquered most of Siberia, largely with the help of the Cossacks and the Stroganov family. Russia had extended to the Pacific Ocean by the end of Michael's reign.