Mayerling is a ballet choreographed by Kenneth MacMillan to the music of Franz Liszt, arranged by John Lanchbery, scenario by Gillian Freeman and designed by Nicholas Georgiadis. The ballet is based on the Mayerling incident, a series of events surrounding the apparent murder–suicide of Rudolf, Crown Prince of Austria and his lover, Baroness Mary Vetsera. The ballet premiered on 14 February 1978, at the Royal Opera House, danced by The Royal Ballet, with David Wall as Prince Rudolf and Lynn Seymour as Vetsera.

Captain William George ("Bay") Middleton was a noted British horseman and an officer of the Royal Lancers. He was equerry to John Spencer, 5th Earl Spencer, Lord Lieutenant of Ireland. When Empress Elisabeth of Austria hunted in Britain, he was her pilot. He was described as "one of the best riders to hounds that ever lived, an amusing dare-devil and very good company."