The Tsarist Empire refers to the period of Russian history when the country was ruled by a series of monarchs known as Tsars. This era began in the early 16th century with Ivan IV, also known as Ivan the Terrible, and lasted until the abdication of Nicholas II in 1917 during the Russian Revolution. The empire expanded significantly, becoming one of the largest in history, encompassing diverse cultures and territories across Europe and Asia. The Tsarist regime was characterized by autocratic rule, where the Tsar held absolute power over the state and its people. The government was supported by a complex bureaucracy and the Russian Orthodox Church, which played a significant role in society. The empire faced numerous challenges, including social unrest, economic difficulties, and military defeats, ultimately leading to its collapse and the establishment of the Soviet Union.