Although the studio initially sought a Frenchman, Italian actor Franco Nero was cast as Lancelot based on recommendations from Harris and John Huston, who worked with Nero on The Bible: In the Beginning... (1966). Although Logan was aware of Nero's thick Italian accent, he initially permitted him to do his own singing. The first scene shot was his performance of the musical number "C'est Moi", after which Logan decided Nero's singing voice was incompatible with the song's musical arrangement. Nero’s singing voice was dubbed by Gene Merlino while Nero was given a speech coach to help improve his English.
