Grand Duke Michael Alexandrovich of Russia (Russian: Михаи́л Александрович; 4 December [O.S. 22 November] 1878 – 13 June 1918) was the youngest son and fifth child of Emperor Alexander III of Russia and youngest brother of Nicholas II.

At the time of his birth, his paternal grandfather Alexander II was still the reigning Emperor of All the Russias. Michael was fourth-in-line to the throne after his father and elder brothers Nicholas and George. After the assassination of his grandfather in 1881, he became third-in-line and, in 1894 after the death of his father, second-in-line. George died in 1899, leaving Michael as heir presumptive.

The birth of Nicholas's son Alexei in 1904 moved Michael back to second-in-line, but Alexei inherited the blood-clotting disorder haemophilia and was not expected to live. Michael caused a commotion at the imperial court when he took Natalia Sergeyevna Wulfert, a married woman, as a lover. Nicholas sent Michael to Orel to avoid scandal but this did not deter Michael, who travelled frequently to see his mistress. After the couple's only child, George, was born in 1910, Michael brought Natalia to St. Petersburg where she was shunned by society. In 1912, Michael shocked Nicholas by marrying Natalia in the hope that he would be removed from the line of succession. Michael and Natalia left Russia to exile abroad in France, Switzerland and England.

After the outbreak of World War I, Michael returned to Russia, assuming command of a cavalry regiment. When Nicholas abdicated on 15 March [O.S. 2 March] 1917, Michael was named as his successor instead of Alexei. Michael, however, deferred acceptance of the throne until ratification by an elected assembly. He was never confirmed as Emperor and, following the Russian Revolution of 1917, he was imprisoned and murdered.

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