born in copenhagen, andersen was first exposed to dance through ballroom dancing. at age 7, he was accepted into the royal danish ballet school, where he studied with kirsten ralov, hans brenaa, flemming ryberg, and vera volkova. he also studied in germany, france, and the united states, where he took classes at the school of american ballet. at age 18, in 1972, he graduated from the copenhagen school into the royal danish ballet as an apprentice. he was accepted into the "corps de ballet" in 1973 and promoted to "solo dancer" (principal) in 1975, when he was 20. at that age, he was the youngest principal dancer in the company's history.