The term "Russian tsars" refers to the emperors of Russia from the 16th century until the early 20th century. The first tsar, Ivan IV, known as Ivan the Terrible, was crowned in 1547. Tsars ruled with absolute power and were seen as the representatives of God on Earth, leading to a strong centralized state. The last tsar was Nicholas II, who reigned from 1894 until his abdication in 1917 during the Russian Revolution. The fall of the tsarist regime marked the end of centuries of imperial rule, leading to the establishment of the Soviet Union.