Sergei Sergeyevich Prokofiev (Russian: Серге́й Серге́евич Проко́фьев, Sergej Sergejevič Prokof’ev; 15/April 271, 1891–March 5, 1953) was a Russian composer who mastered numerous musical genres and came to be admired as one of the greatest composers of the 20th century. (Alternative transliterations of his name include Sergey or Serge, and Prokofief or Prokofieff.)
Sergei Pavlovich Diaghilev (Russian: Серге́й Па́влович Дя́гилев Sergej Pavlovič Dâgilev), also referred to as Serge, (March 31, 1872 – August 19, 1929) was a Russian art critic, patron, ballet impresario and founder of the Ballets Russes from which many famous dancers and choreographers would later arise.
Sergei (1857-1905) was the son of Emperor Alexander II of Russia and his wife Maria. His older brother was Emperor Alexander III. He was married to Elisabeth of Hesse, the older sister of Alexandra, last Czarina of Russia. He was assassinated.