Development
Producer Euan Lloyd was introduced to Louis L'Amour, author of numerous Western adventure novels, by his actor friend Alan Ladd. Over the years, as Lloyd dreamed of becoming an independent producer, he kept in touch with L'Amour. He wanted to film his 1962 novel Shalako. In 1965 Lloyd announced he had the rights.
Lloyd offered the project to director Edward Dmytryk when the latter was preparing Anzio. Dmytryk felt "the story was interesting, script awful" and agreed to direct if Lloyd had the script rewritten by an actor friend of the director, Jim Griffith. The producer acquiesced and Dmytryk said the new script "wasn't Shane or even Warlock but it wasn't bad." However he doubted Lloyd would be able to get the necessary stars to finance the movie. At one time, Lloyd had lined up Henry Fonda and Senta Berger to star in the film, planning to shoot it in Mexico. This was announced in 1966. Lloyd later recounted that, at the time, many film distributors were reluctant to back a film starring Fonda, and increases in the cost of filming in Mexico made it impossible to pursue.
During a meeting with L'Amour, Lloyd recounted long lines at the cinemas in New York City for the latest James Bond adventure film. L'Amour remarked that Sean Connery, who starred in the role, would certainly "look tall in the saddle". When Lloyd met Sean Connery and discussed the work with him, he learned that Connery was a Western fan since childhood. He was also keen to do the film as he had been promised $1 million and 30% of the profits out of the $5 million budget. Connery's casting was announced in June 1967.
Connery was available, as he had turned down playing Bond in On Her Majesty's Secret Service. Lloyd obtained that film's planned original co-star Brigitte Bardot, Bond cinematographer Ted Moore, and Bond stuntman and action scene arranger Bob Simmons. Bardot turned down the female lead in On Her Majesty's Secret Service for Shalako. She was paid $400,000 plus 12.5% of the profits. It was her second Western, the first being Viva Maria (1965). The second female lead, Honor Blackman, had appeared opposite Connery in Goldfinger. Lee Radziwill was reportedly considered for a role.
Once Lloyd had Connery on board, many European and other film distributors were keen to finance the film. Distributors in 35 different countries agreed to provide promissory notes worth $5 million payable on delivery of the film. This enabled Lloyd to raise the $3 million necessary to start production and to sign Connery and Bardot. $1,455,000 of the budget came from the American company Palomar, a subsidiary of the ABC network with $2 million from elsewhere. Dimitri de Grunwald became involved in helping finance. Nat Cohen of Anglo-Amalgamated agreed to distribute in the UK.
Lloyd gathered a strong international cast, including Connery's former co-star Honor Blackman from Goldfinger, as well as Jack Hawkins, Stephen Boyd, Woody Strode, Peter van Eyck, Alexander Knox, Eric Sykes, and Don Barry. At this stage in his career Hawkins had lost his once-booming voice to throat cancer, his voice was dubbed by Charles Gray; this was Hawkins' second appearance after the operation the first being The Great Catherine. Woody Strokde agreed to play an Indian chief if his friend, Tug Smith, was cast alongside him.