Terry Southern of the Monty Python team. Cleese later described McGrath as having "no idea of comedy structure" and complained that the film ended up as "a series of celebrity walk-ons." The film was shot in London between February and May 1969. The cast was headed by Sellers (as Guy Grand) and Ringo Starr as his son Youngman Grand (a new character created for the movie), with cameo appearances by Spike Milligan, Christopher Lee, Laurence Harvey, Raquel Welch, Roman Polanski and Yul Brynner. As with "Dr Strangelove", Sellers habitually improvised on the script during filming. During production McGrath and Southern discussed a
Dr. Strangelove were "Dr. Doomsday or: How to Start World War III Without Even Trying", "Dr. Strangelove's Secret Uses of Uranus", and "Wonderful Bomb". After deciding to make the film a black comedy, Kubrick brought in Terry Southern as a co-writer in late 1962. The choice was influenced by reading Southern's comic novel "The Magic Christian", which Kubrick had received as a gift from Peter Sellers, and which itself became a Sellers film in 1969. Southern made important contributions to the film, but his role led to a rift between Kubrick and Peter George; after "Life" magazine published a photo-essay on Southern