Richard Harris desperately sought the lead role, despite being repeatedly refused due to his limited singing ability. At one point he even paid a man to carry a board down the Strand that said, "Harris Better than Burton, Only Harris for Camelot". When Vanessa Redgrave was cast as Guenivere, Harris sent a note to producer Jack L. Warner, which read, "Height of Vanessa Redgrave: 5 feet 11 inches. Richard Burton: 5 feet 10 inches. Richard Harris: 6 feet 2 inch," according to his salute for Kirk Douglas at AFI ceremony.
At one point, while filming on a Warner Bros. soundstage, Richard Harris and producer Jack L. Warner were at odds over how to do a scene. Warner took Harris out onto the studio lot, and showed him the famous water tower with the Warner Bros. logo on it. "What does that tower say, Richard?" asked Warner. "It says 'Warner Brothers,'" Harris replied. "Right," said Warner. "Now when it says 'Harris Brothers,' *then* we'll do it *your* way."
Julie Andrews was asked to reprise her stage role of Guenevere, but had become such a popular film star by this time that she was unable to accept the role. Ironically, Jack L. Warner, who produced the movie version of Camelot (1967), was the same man who produced the film version of My Fair Lady (1964), and who had given the role of Eliza Dolittle to Audrey Hepburn because he thought that Julie Andrews would not be a big enough box-office name. Warner apologized to Andrews on his troubles about the My Fair Lady casting and the two became in good standing with each other from that moment forward. Andrews, ultimately, did not get to reprise her role, because the film's director Joshua Logan wanted Vanessa Redgrave for the role, instead.
Vanessa Redgrave and Franco Nero who met on this film would later on in life get married and have a child together (Carlo Gabriel Nero). They have also worked together since in Letters to Juliet (2010) as lovers who found each other after years apart.
Richard Harris and David Hemmings became lifelong friends and Harris never forgot the time Hemmings talked him out of suicide. During one rocky period in the film's production, Hemmings had come to collect Harris from his house in the Hollywood Hills. When he arrived, he found Harris on a balcony above the swimming pool. "I'm going to jump", Harris announced. "You can't do that", Hemmings protested. "There's no water in the pool". Harris replied, "I don't give a fuck. I fucking hate Warner Brothers and fucking Hollywood, the people here are all fucking arseholes". Hemmings climbed out on to the balcony. "Are you sure you really want to do this?" Harris' face fell. "No, I don't. Let's have a drink".
In addition to actual Medieval castles in Spain used in this film, a castle was built on the back lot of Warner Brothers Studios for closer shots and direct storyline action. Long known at the studio as the "Camelot Castle" after filming ended, it was used in other films. In 1972, the Camelot Castle was renovated into a Tibetan Lamasery for the musical remake of Lost Horizon (1973), and it was used extensively in the TV series Kung Fu (1972). In the 1980's, the back lot castle was torn down to make room for an office building. Fortunately, the Alcazar de Segovia and the Coca Castle remain in Spain where they are both popular tourist attractions.
Two separate Medieval castles in Segovia, Spain, were used in this motion picture; one as Sir Lancelot's Castle in France and the other as Camelot itself in various long shots. The Alcazar de Segovia, with its mansard roofs and numerous turrets reminiscent of Disneyland's Sleeping Beauty's castle, was depicted as Sir Lancelot's home in Gaul (France) in the film. The opening and closing scenes were also filmed on the grounds of this same castle which may be seen in the background in the light of the approaching dawn. For Camelot itself, the Coca Castle, also in Segovia, was used in long shots and background shots to depict the towers and battlements of Arthur's legendary kingdom.
Richard Burton, who had played the role of King Arthur on Broadway in the original 1960 production, was offered the role in the film. Burton had had a huge success with Lerner & Lowe's show, winning a 1961 Tony Award for Best Actor in a Musical, but he turned the film down; a decision he would regret later on. Burton subsequently played King Arthur in a 1980 touring revival of "Camelot", to make up for his prior decision, although he had to drop out in April, 1981, due to ill health and was replaced by Richard Harris.
In the original musical, Merlin is lured away from Camelot by the spirit of Nimue, who sings the song "Follow Me." Nimue was dropped from the film, and the song is sung by a chorus during the last of the scenes with Merlin.
The song "If Ever I Would Leave You" won a Golden Globe Award for Best Original Song Written for a Motion Picture, even though it was not written especially for the film but for the original stage production of "Camelot", and all the other nominees were songs especially written for films. In addition Frederick Loewe won a Golden Globe for "Best Original Score", a score that he had actually written for the Broadway stage, not for films. This is the only instance in the history of the Golden Globe Awards that this has happened.
Because Warner Brothers was a dry studio, drinking buddies Richard Harris and David Hemmings smuggled in alcohol in a prop van and discarded the empty bottles in a couple of portaloos. One afternoon, Jack L. Warner was showing a group of distinguished Japanese tourists around the studio when one lady was suddenly caught short and rushed to Harris' portaloo and opened it, causing bottles to crash out. Harris grabbed the woman and ran off, leaving Hemmings alone with a suitably embarrassed Warner. When Harris returned, he ordered the crew to clean up the mess and as he let with his guests, he whispered out of the corner of his mouth to the two actors, "This bar is now closed".
When Richard Burton was considered to reprise his stage role as King Arthur, Warners considered casting Elizabeth Taylor as Guinevere and Peter O'Toole as Lancelot. This was scrapped for being potentially too expensive.
At a celebrity bash, David Hemmings began playfully sparring with his fellow guests. Richard Harris took offence to this and, demonstrating his own boxing prowess, landed a punch that split Hemmings' lip. Upon seeing this, Vanessa Redgrave burst into tears and announced that she'd never work with Harris again.
Jack L. Warner initially refused to let Joshua Logan film in Europe, demanding that the whole production be filmed on the Warners back lot. Through a strange quirk of fate, Warner soon relented his decision after receiving some tax loophole advice by his creative accounting department and gave Logan the green light.
Joshua Logan chose Vanessa Redgrave for Guinevere after seeing her in Morgan! (1966), but he had to wait several months to get her since she was committed to a play in London - "The Prime of Miss Jean Brodie".
Richard Harris insisted on cutting Lancelot and Guinevere's love scene, because he felt that it reduced the dignified aspects of the king. When Jack L. Warner refused to comply, Harris burst into his office and started pounding on the desk.
After scouting various shooting locations, Joshua Logan decided not to film in England despite a surplus of medieval castles there. The reason being, according to his autobiography, that "the castles in England are either in ruins or have modern additions, whereas Spain is filled with entire castles that were built in the Middle Ages." Eventually the director chose the castle at Coca, Spain for Camelot and the elegant Alcazar in Segovia for Lancelot's fortress, Joyous Gard.
As expected for a production of this magnitude, there were plenty of headaches and problems to solve during the filming. The jousting stunts had to be worked out carefully and safely, the knights' armor (composed of a synthetic rubber) had to be pliable and relatively lightweight, the period detail right down to Guenevere's bridal bouquet at her wedding had to be authentic, etc.
Vanessa Redgrave insisted on "creative" enhancements to her dialogue, costumes, and character. For one musical number which accents Guenevere's playful attitude towards Lancelot, she baffled Joshua Logan by singing her lyrics in French. When questioned as to why, she said, "We're making fun of Lancelot, aren't we? And he's French. Well, the whole idea is that by singing it in French we're making more of a joke of him." Luckily, after an exhausting debate, Logan managed to get her to record the lyrics in English.
Joshua Logan saw the film as an opportunity to correct the faults he found with the Broadway musical, despite its huge success. For one thing, he thought Richard Burton made a very distracted, absent-minded king and he felt that Julie Andrews was too wholesome as Guenevere whom he saw as a true femme fatale. The biggest problem for Logan though was the character of Lancelot In Logan's, he wrote that Lancelot is "probably the most difficult part to play....Lancelot is French and has come across the Channel to espouse Arthur's passionate cause. He happens to be a holy young man who is able to perform miracles, including bringing back to life one of the knights he has killed in jousting. He does this by praying. And shortly thereafter he readily goes to bed with Arthur's wife. Lancelot is, so to speak, a holy cad. All of which makes him very difficult to play."