At the time, the largest film production ever in Sweden (with 60 speaking parts and over 1200 extras) and the most expensive, with a budget of $6 million.
Famous Swedish song-and-dance man Jan Malmsjö, who is playing the evil bishop Vergérus, thought it was strange that director Ingmar Bergman approached him for a role very much different from anything he had done. He asked Bergman about it, who replied: "Well, I sense some hidden dark and evil streaks inside you, Jan. You have it, I have it, all of us have."
Ingmar Bergman wanted to kick off the six-month-long shoot with "something light and happy", so the first scene that was shot was the wild pillow fight featuring all the children.
The part of Bishop Edvard Vergérus was written by Ingmar Bergman with Max von Sydow in mind. When the screenplay was completed, von Sydow was contacted about playing the role, which would have been his first in a Bergman film since The Touch (1971). Von Sydow was willing and, in fact, very excited about playing the role. However, Bergman was not aware of this, since von Sydow was in Los Angeles at the time, and could only be reached through his agent who, acting in what he perceived as von Sydow's interest, told Bergman and his producers that von Sydow would only play the role if he could have a percentage of the film's profits, in addition to his salary. The producers, already stretched to their financial limits, of course balked, and told the agent that, sadly, there could be no such compromise, and began looking for other actors to play the pivotal part. By the time von Sydow had learned why his beloved role had been taken from him, Jan Malmsjö had already been cast as the Bishop, and von Sydow lost his chance to star in what would later be known to be Bergman's "last film" (although he would play key roles in The Best Intentions (1992) and Private Confessions (1996), both written by Bergman). Von Sydow was furious about the incident, and, by certain accounts, still harboured a bitter grudge about for the remainder of his life.
Ingmar Bergman's first draft of the script, completed in 1979, consisted of about 1,000 handwritten pages.