Quixote, which premiered in May 1965; Balanchine's creation of that ballet was thought to be a valentine to his newest "muse", and Balanchine performed in the role of Don Quixote on opening night. In 1968, he cast her as the lead in the "Diamonds" section of his three-act plotless ballet Jewels. She re-scaled many ballets and expanded them to a new level of technique. In 1965, she was promoted to principal dancer. Her first role in her new title was Agon with Arthur Mitchell at the Paris Opera. George Balanchine quickly fell in love with his "alabaster princess" and created many roles for her. Farrell described learning choreography from Balanchine as a collaborative process, saying, "When Mr. B was working on a ballet, something would just spill out of his body; he could rarely duplicate it, so I tried to see precisely what he wanted the first time." Balanchine was married to the polio-stricken former ballerina Tanaquil Le Clercq, however, and Farrell was a Catholic. Though Balanchine divorced LeClercq to pursue Farrell, she instead married fellow dancer Paul Mejia. This caused the relationship of Farrell and Balanchine to fracture. There was enormous tension between them, which caused Farrell and husband Mejia to leave the company. Mejia and Farrell were married from 1969 to 1997. She and her husband later joined the European company Ballet of the 20th Century of the French choreographer Maurice Béjart, based in Brussels. With this company she danced leading roles, some created for her, for four years, exploring a style of choreography completely different from Balanchine's. She eventually returned to Balanchine and the New York City Ballet in 1975. Balanchine continued to create new ballets for her, such as Chaconne, Mozartiana, Tzigane and Robert Schumann's Davidsbündlertänze. Farrell also found herself often paired with the Dane Peter Martins. Her partnership with Balanchine lasted until his death in April 1983; his last works were solos for Farrell. Farrell retired from the New York City Ballet at age 44 on November 26, 1989, after being fired by Martins due to her three year long absence from the stage, which was caused by her arthritis. She performed Sophisticated Lady and Vienna Waltzes. Farrell gave her final bow at State Theater with New York City Ballet co-founder Lincoln Kirstein by her side. Career as a dance teacher Twenty-eight years of an occupation which takes a tremendous physical toll on the body