The film had its origins in
Orson Welles' attempts to film his Shakespearean play
Chimes at Midnight (1965) in the early 1960s - a project he had worked on since the late 1930s. After Welles had failed to convince numerous producers to finance his film, he tried an alternative approach: he wrote a screenplay for the more commercially appealing Treasure Island, and promised to make both films, back to back, filmed on the same sets and with the same cast, for barely more than the cost of one film. As well as having written the script, he proposed to direct
Treasure Island (1965) and play Long John Silver. This approach worked; Spanish producer
Emiliano Piedra agreed to finance both films, and color filming on Treasure Island by Welles actually began in 1964 (while Chimes at Midnight was simultaneously shot in black and white). However, Piedra's interest in Chimes at Midnight was minimal, and when Welles felt he was being given inadequate resources for the Chimes shoot, he began appropriating resources from Treasure Island to be able to complete the more cherished project. Treasure Island was thus effectively abandoned after a few days of filming. However, Welles remained contractually tied to the project as both actor and writer, and eventually, eight years later, he was brought in to make the film
Treasure Island (1972) for the director
John Hough. Once again, it was filmed entirely on location in Spain, with a Spanish crew. Welles was sufficiently dismissive of the rewrites to his original script that he asked not to be credited, taking the pseudonym "O.W. Jeeves".