Eugene Onegin is an opera in three acts by Pyotr Il'yich Tchaikovsky in 1878. Tchaikovsky's opera was written at the difficult period of his marriage to an apparently infatuated and certainly unbalanced admirer and their immediate separation. It was completed abroad in Switzerland and Italy. Of particular poignancy is Tatyana's Letter Scene and OneginÃ¢â‚¬â„¢s subsequent answer in the garden. Prince Gremin's aria in the third act gives depth to his character, as he describes the effect on him of his marriage to the young Tatyana. The dances from the two ball scenes have provided concert audiences with orchestral excerpts from the score.