Pyotr Ilyich Tchaikovsky (May 7, 1840 - November 6, 1893) was a Russian composer whose works included symphonies, concertos, operas, ballets, chamber music, and a choral setting of the Russian Orthodox Divine Liturgy. Some of these are among the most popular theatrical music in the classical repertoire. He was the first Russian composer whose music made a lasting impression internationally, which he bolstered with appearances as a guest conductor later in his career in Europe and the United States. Despite his many popular successes, Tchaikovsky's life was punctuated by personal crises and depression. Contributory factors included his leaving his mother for boarding school, his mother's early death, as well as that of his close friend and colleague Nikolai Rubinstein, and the collapse of the one enduring relationship of his adult life, his 13 year association with the wealthy widow Nadezhda von Meck. His homosexuality, which he kept private, has traditionally also been considered a major factor, though some musicologists now downplay its importance. His sudden death, in 1893 at the age of 53, is generally ascribed to cholera; there is an ongoing debate as to whether it was accidental or self-inflicted.