Russian Grand Duke as the fifth son and seventh child of Emperor Alexander II of Russia. He was an influential figure during the reigns of his brother Emperor Alexander III of Russia and his nephew Emperor Nikolai II, who was also his brother in law through Sergei’s marriage to Elizabeth the sister of Tsarina Alexandra.
Grand Duke Sergei’s education gave him lifelong interests in culture and the arts. Like all male members of the Romanov dynasty, he followed a military career, and he fought in the Russo-Turkish War of 1877–1878, receiving the Order of St George for courage and bravery in action. In 1882, his brother, Tsar Alexander III, appointed him Commander of the 1st Battalion Preobrazhensky Life Guard Regiment, a position he held until 1891. In 1889, Grand Duke Sergei was promoted to the rank of Major General.
In 1884, Sergei married Princess Elisabeth of Hesse and by Rhine, a granddaughter of Queen Victoria. Their marriage remained childless, but they became the guardians of the two children of his brother, Grand Duke Paul Alexandrovich of Russia: Grand Duchess Maria, and Grand Duke Dimitri.
Between 1891 and 1905, Grand Duke Sergei served as Governor General of Moscow. His reputation was tarnished as he was partially blamed by the Khodynka Tragedy, which, during the festivities following the coronation of Emperor Nicholas II, resulted in thousands of deaths. As a Governor of Moscow, Grand Duke Sergei was responsible for the expulsion of Moscow’s 20,000 Jews at the start of his tenure, and he repressed a student movement to prevent the spread of revolutionary ideas. His conservative policies, extreme even by contemporary standards, made him a polarizing figure, and he was regarded as a reactionary.
Targeted by the SR Combat Organization, he was assassinated by a terrorist bomb at the Kremlin on 17 February 1905, aged 47.
Link to Wikipedia biography