The movie was Paul Verhoeven's reaction to the many movies that, in his view, overly romanticized the Middle Ages; he wanted to show it as a period where brutality, disease, poverty and hardship were common, and a natural death was a rare thing.
The production was plagued by adversities. There was great animosity among the Spanish, American and Dutch crew and cast members; actors were using alcohol and drugs on the set, while wind, heavy snowfall and cold often disrupted filming, causing the movie to go over budget. Director Paul Verhoeven would later call it the worst filming experience of his life, one that made him consider quitting making movies altogether.
This was Paul Verhoeven's last project in the Netherlands for two decades. He attended the Dutch film festival, at which the film premiered, and took a plane to the US the very next morning in order to start his American debut, RoboCop (1987).
There was so much competition for screen presence among the actors that some of them started to call the movie "Flesh + Blood + Elbows", in the sense that some cast members would literally use their elbows to push others out of frame.
Paul Verhoeven wanted to explore the idea of a confrontation between two allies who had become enemies, stating that he had always been a bit disappointed that the two enemies in The Wild Bunch (1969) never really met face to face. One of the scenes he had in mind for this movie showed Martin and Hawkwood having a calm conversation in a bathtub, while both conceal a knife. The characters would have a final showdown at the end of the movie. However, the studio wanted a bigger part for the character of Agnes and more focus on the love story, so the audience could better identify with the main characters. The bathtub scene therefore became a love scene, and the feud between Martin and Hawkwood was pushed to the background, much to Verhoeven's later regret.
Orion Pictures kept asking Paul Verhoeven for a war movie like his previous film Soldier of Orange (1977). Since he did not have one readily available, he and screenwriter Gerard Soeteman hastily produced a brief story outline concerning a medieval group of mercenaries, a project that they had conceived more than ten years before, but abandoned to do other movies.
The character named "Hawkwood" was probably named after Sir John Hawkwood (1320-94), who was an actual historical figure. He commanded a band of condottiere--mercenaries--known as "The White Company" in Italy in the 14th century.
Paul Verhoeven decided for the first time not to storyboard the entire movie and adopt a more improvisational style of directing; a decision that he quickly regretted, given the enormously complex nature of the production.
The movie was greatly inspired by The Wild Bunch (1969) (which also dealt with two former allies who become enemies), Vera Cruz (1954) and The Crimson Pirate (1952). Suggested titles for the movie were "The Mercenaries" and "God's Own Butchers" before settling on "Flesh + Blood" (which was the title of a recent Roxy Music album at the time).
First ever English-language theatrical feature film of Dutch director Paul Verhoeven following his very successful career in Holland (aka the Netherlands) which notably had included Spetters (1980), Soldier of Orange (1977) (aka "Soldier of Orange"), and Turkish Delight (1973) (aka "The Sensualist" aka "Turkish Delight").
The movie was awarded two prizes at the Dutch Film Festival (Best Picture and Best Director), but several jury members publicly attacked this decision afterwards, stating that the vote had not been unanimous.