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.
List of Russian rulers
The Empire of Russia was declared by Peter the Great in 1721. Officially, Russia would be ruled by the Romanov dynasty until the Russian Revolution of 1917. However, direct male descendants of Michael Romanov came to an end in 1730 with the death of Peter II of Russia, grandson of Peter the Great. The throne passed to Anna, a niece of Peter the Great, and after the brief rule of her niece's infant son Ivan VI, the throne was seized by Elizabeth, a daughter of Peter the Great. Elizabeth would be the last of the direct Romanovs to rule Russia. Elizabeth declared her nephew, Peter, to be her heir. Peter (who would rule as Peter III) spoke little Russian, having been a German prince of the House of Holstein-Gottorp before arriving in Russia to assume the Imperial title. He and his German wife Sophia changed their name to Romanov upon inheriting the throne. Peter was ill-liked, and he was assassinated within six months of assuming the throne, in a coup orchestrated by his wife, who became Empress in her own right and ruled as Catherine the Great (both Peter and Catherine were descended from the House of Rurik). Following the confused successions of the descendants of Peter the Great, Catherine's son Paul I established clear succession laws which governed the rules of primogeniture over the Imperial throne until the fall of the Empire in 1917.
Nicholas II abdicated in favour of his brother, Grand Duke Michael Alexandrovich, but the next day, after a nominal reign of only 18 hours, "Emperor Michael II" abdicated, ending dynastic rule in Russia forever. (He is not normally considered to be the last tsar.)