Tsars were the emperors of Russia, ruling from the 16th century until the early 20th century. The title "tsar" is derived from the Latin word "Caesar," reflecting the authority and power these leaders held. Tsars governed with absolute power, often making decisions without consulting others, and were seen as the representatives of God on Earth. The most famous tsar was Peter the Great, who modernized Russia in the late 17th and early 18th centuries. The last tsar, Nicholas II, ruled until the Russian Revolution in 1917, which led to the end of the monarchy and the establishment of a communist government.