Here is a little bit of interesting information I learned over the holidays. George Balanchine was one of the 20th century's most important choreographers and one of the founders of American ballet.
He trained at Imperial Ballet School until the revolution. When the school reopened, he re-enrolled and graduated in 1921, at the age of 17.
While still in his teens, Balanchine choreographed his first work, a pas de deux called La Nuit . This was followed by another duet, Enigma, danced in bare feet. When he was 19 he formed a small ensemble, the Young Ballet which was declared too experimental for the who strongly encouraged the group to disband.
He also danced in the Nutcracker at age 17 and later went on to choreograph the most beloved version of the ballet today.