Sergei Sergeyevich Prokofiev (Russian: Сергей Сергеевич Прокофьев, tr. Sergej Sergeevič Prokof'ev; 15/27 April 1891 – 5 March 1953) was a Russian composer, pianist and conductor. As the creator of acknowledged masterpieces across numerous musical genres, he is regarded as one of the major composers of the 20th century. His works include such widely heard works as the March from The Love for Three Oranges, the suite Lieutenant Kijé, the ballet Romeo and Juliet – from which "Dance of the Knights" is taken – and Peter and the Wolf. Of the established forms and genres in which he worked, he created – excluding juvenilia – seven completed operas, seven symphonies, eight ballets, five piano concertos, two violin concertos, a cello concerto, and nine completed piano sonatas. A graduate of the St Petersburg Conservatory, Prokofiev initially made his name as an iconoclastic composer-pianist, achieving notoriety with a series of ferociously dissonant and virtuosic works for his instrument, including his first two piano concertos. In 1915 Prokofiev made a decisive break from the standard composer-pianist category with his orchestral Scythian Suite, compiled from music originally composed for a ballet commissioned by Sergei Diaghilev of the Ballets Russes. Diaghilev commissioned three further ballets from Prokofiev – Chout, Le pas d'acier and The Prodigal Son – which at the time of their original production all caused a sensation among both critics and colleagues. Prokofiev's greatest interest, however, was opera, and he composed several works in that genre, including The Gambler and The Fiery Angel. Prokofiev's one operatic success during his lifetime was The Love for Three Oranges, composed for the Chicago Opera and subsequently performed over the following decade in Europe and Russia. After the Revolution, Prokofiev left Russia with the official blessing of the Soviet minister Anatoly Lunacharsky, and resided in the United States, then Germany, then Paris, making his living as a composer, pianist and conductor. During that time he married a Spanish singer, Carolina Codina, with whom he had two sons. In the early 1930s, the Great Depression diminished opportunities for Prokofiev's ballets and operas to be staged in America and western Europe. Prokofiev, who regarded himself as composer foremost, resented the time taken by touring as a pianist, and increasingly turned to Soviet Russia for commissions of new music; in 1936 he finally returned to his homeland with his family. He enjoyed some success there – notably with Lieutenant Kijé, Peter and the Wolf, Romeo and Juliet, and perhaps above all with Alexander Nevsky. The Nazi invasion of the USSR spurred him to compose his most ambitious work, an operatic version of Leo Tolstoy's War and Peace. In 1948 Prokofiev was criticized for "anti-democratic formalism" and, with his income severely curtailed, was forced to compose Stalinist works, such as On Guard for Peace. However, he also enjoyed personal and artistic support from a new generation of Russian performers, notably Sviatoslav Richter and Mstislav Rostropovich: for the latter, he composed his Symphony-Concerto, whilst for the former he composed his ninth piano sonata.