Who was the last Tsar of Russia, who abdicated in 1917?

Nicholas II was the last Tsar of Russia, abdicating in 1917. He became Emperor of Russia in 1894 after the death of his father, Alexander III, and was the final ruler of the Romanov dynasty.

His reign was strained by military defeats, political unrest, economic hardship, and the enormous pressures of World War I. The February Revolution of 1917 brought strikes and mutinies to Petrograd, leaving Nicholas without reliable control of the capital. He abdicated on March 2, 1917, under the old Russian calendar, equivalent to March 15 in the Gregorian calendar then used internationally.

Nicholas initially considered abdicating for his son Alexei, who had hemophilia, but ultimately renounced the throne on behalf of both himself and Alexei in favor of his brother, Grand Duke Michael. Michael declined to become emperor without popular approval, effectively ending the monarchy.

A common mix-up is Alexander III, Nicholas's predecessor, who was not the last Tsar. Nicholas and his family were later imprisoned and executed by the Bolsheviks in Yekaterinburg in July 1918.