Boris Kochno was a Russian poet, dancer and librettist.
He was a lover of Karol Szymanowski while a schoolboy of fifteen in Elisavetgrad (now Kirovohrad) in 1919, where he received as a gift a Russian translation of the chapter The Symposium from Efebos, the composer's unpublished novel on male love. Szymanowski also dedicated four love poems to the youth.
In 1920 he became Sergei Diaghilev's secretary, librettist, and eventually main collaborator. They were also lovers until Diaghilev's death in 1929 at 57. Kochno wrote the libretto of Mavra (1921), the Fâcheux (1924), La Chatte (1927) and of le Fils prodigue(1929). He also had an affair with Cole Porter in 1925, with whom he carried on a lengthy correspondence.
Upon Diaghilev's death he and Serge Lifar tried but failed to hold the Ballets Russes together. The two inherited part of Diaghilev's archives and collections, which Kochno completed and part of which was acquired by the Bibliothèque Nationale de France. His later career included a position as Monte Carlo ballet director, where he became an influential figure in post-WWII French ballet. In 1933 he co-founded, together with George Balanchine, the short-lived company Les Ballets 1933, which made its debut that summer at the Théâtre des Champs-Élysées. At the end of WWII, Kochno entered into collaboration with Roland Petit, with whom he founded the Ballets des Champs-Élysées.
There are a number of published works by him. One, Diaghilev and the Ballets Russes, is a record of the Diaghilev era. The other, Christian Bérard, is a scrapbook of reminiscences about, and art of, his former friend and collaborator.