Probably the only movie to have its world premiere in Limerick , Ireland. This took place on November 6, 1970.
Maurice Gibb of the Bee Gees co-wrote the theme song, "The Loner". The artist credit, "The Bloomfields", is a pseudonym for Maurice Gibb and Billy Lawrie. Billy Lawrie is the brother of pop singer Lulu and was Maurice Gibb's brother-in-law at the time.
Future "Harry Potter" producer David Heyman plays one of the young fans. His father, John Heyman, was one of the producers.
Romy Schneider and Richard Harris had a passionate affair during filming according to her biographers.