"Monty Python and the Holy Grail" is considered one of the greatest comedies of all time, but it had a rather complicated development. Cast member John Cleese has revealed that "Holy Grail" didn't start out as a medieval comedy; the film only took the full plunge into the genre when co-star Michael Palin came up with a joke about King Arthur and coconuts.

The Monty Python troupe faced writer's block with "Holy Grail," which began as a simple comedy anthology film. One idea was for a sketch set in medieval times; the crew knew they couldn't afford to use real horses, so Palin suggested that the actors would mime riding horses, while their servants clacked empty coconut halves together to mimic hoofbeats.

Palin's idea grew into a sketch about a pair of men atop a castle wall, questioning King Arthur about how coconuts ended up in England. Cleese recalls that more and more jokes and ideas spawned from this single gag, until the crew decided, "Right, it’s all going to be set in medieval times"; thus, the epic "Holy Grail" we know and love today.