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
From its initial creation until the 1905 Revolution, the Russian Empire was controlled by its tsar/emperor as an absolute monarch, under the system of tsarist autocracy. After the Revolution of 1905, Russia developed a new type of government which became difficult to categorize. In the Almanach de Gotha for 1910, Russia was described as "a constitutional monarchy under an autocratic tsar". This contradiction in terms demonstrated the difficulty of precisely defining the system, essentially transitional and meanwhile "sui generis", established in the Russian Empire after October 1905. Before this date, the fundamental laws of Russia described the power of the Emperor as "autocratic and unlimited". After October 1905, while the imperial style was still "Emperor and Autocrat of All the Russias", the fundamental laws were remodeled by removing the word "unlimited". While the emperor retained many of his old prerogatives, including an absolute veto over all legislation, he equally agreed to the establishment of an elected parliament, without whose consent no laws were to be enacted in Russia. Not that the regime in Russia had become in any true sense constitutional, far less parliamentary. But the "unlimited autocracy" had given place to a "self-limited autocracy". Whether this autocracy was to be permanently limited by the new changes, or only at the continuing discretion of the autocrat, became a subject of heated controversy between conflicting parties in the state. Provisionally, then, the Russian governmental system may perhaps be best defined as "a limited monarchy under an autocratic emperor".