In AD 932, King Arthur (Graham Chapman) and his squire Patsy (Terry Gilliam) travel throughout Britain, searching for men to join the Knights of the Round Table, as they debate whether swallows can carry coconuts. They pass through a town infected with the Black Death, Arthur tells of receiving Excalibur from the Lady of the Lake to a pair of Anarcho-Syndicalist peasants, and they observe a witch trial. Arthur recruits several knights—Sir Bedivere the Wise (Terry Jones), Sir Lancelot the Brave (John Cleese), Sir Galahad the Pure (Michael Palin), and Sir Robin the Not so Brave as Sir Lancelot (Eric Idle). Also: their squires and Robin’s minstrels.
Arthur considers going to Camelot, but after a musical number he decides it is a silly place. God appears and tells Arthur to find the Holy Grail. They arrive at a castle occupied by French soldiers who claim they have the Grail and launch barnyard animals at them. Bedivere suggests a Trojan Rabbit to get in, but they forget to hide inside it. They decide to separate and search for the Grail independently. A modern-day historian is run through by a knight on horseback and the police investigate.
Arthur and Bedivere have to deal with the Knights Who Say Ni. Sir Robin flees from a three-headed giant while the heads are arguing. Sir Galahad finds a flashing neon Grail sign at Castle Anthrax, which is full of young women wanting to be spanked, but the other knights save him from almost certain temptation. An arrow sends a note from someone begging to be freed from imprisonment in a castle, and after slaughtering much of a wedding party, Lancelot discovers the note was a fake. He listens to the story of the castle that burned down, fell over, and sank into the swamp.
The Knights are joined by more knights and by Brother Maynard (Eric Idle) and his fellow monks. Tim the Enchanter (John Cleese) directs them to a cave where they are assaulted by a killer rabbit, which they dispatch with a Holy Hand Grenade. They find an inscription by Joseph of Arimathea, directing them to the Castle Aarrgh, they are attacked by an animated cave-monster and approach the Bridge of Death, where some are cast into the Gorge of Eternal Peril because they cannot answer the Questions Three. They are unable to find Lancelot, who has been arrested by the police. Just as they are about to assault a castle full of French Knights, they are arrested by the police as well, who break their camera, ending the film.
It might seem strange to begin this list of fantasy films with a comedy poking fun at the entire genre, but this is actually a pretty good introduction to fantasy films. Most of the Pythons came out of Oxford and Cambridge Universities and were quite thoroughly versed in the Arthurian legends, which they needed to be for audience recognition. Contrast this with Camelot, which came out earlier. Holy Grail is filled with swordplay and wizardry, castles and monsters, and holy quests, while Camelot is basically a musical about a love-triangle, the least important part of the Arthurian story.
The film was directed by Terry Gilliam and Terry Jones, the first film by the Pythons. Later, Eric Idle was to use the film as the basis of the Tony-winning musical Spamalot. This was the highest grossing British film that year and has since been declared the second-best comedy of all time, after Airplane! It was financed by Led Zeppelin, Pink Floyd, part of Jethro Tull, Elton John, and a soccer team. No studio wanted to finance it and the rockers thought it a good tax write-off. Because they could not afford horses, the cast mimed horse-riding with coconut sound-effects. No Killer Rabbits were harmed in the filming, though they had a hard time cleaning off the fake blood. At a screening, Terry Jones noticed that when music was played during the jokes there was less laughter in the audience, so he edited out the music during punchlines.
When the projector stopped during the movie at Cannes, the audience laughed, thinking it was part of the film. But it was actually a bomb-scare. The airspeed velocity of an unladen swallow is eleven meters per second. Several Medieval cathedrals, as an example of the vice of cowardice, actually depict a knight running from a rabbit. Eric Idle was asked what their next film might be and he ad-libbed Jesus Christ: Lust for Glory. This later resulted in Life of Brian. At a screening in New York, the Pythons were fawned over by John Belushi and Gilda Radner, who were just beginning their careers. A Monty Python fan turned up on the set one day and was given various roles, such as a prisoner hanging on a wall. Needing a stuffed sheep thrown at King Arthur and not having one, they used a dead sheep they found on the side of the road.