There’s an old notion that Geoffrey Chaucer, author of the Canterbury Tales collection of stories, is the inspiration for April Fool’s Day. According to the theory, in the Nun’s Priest’s Tale, the vainglorious cockerel Chauntecleer explains that he was tricked by a sly fox, “Syn March bigan thrifty dayes and two”—which some readers take to mean March 32nd (i.e. April 1). The tricking of Chaucer’s cockerel, ultimately, is said to have inspired a day on which it’s perfectly acceptable to pull pranks and practical jokes.

It’s a nice theory, certainly, but unfortunately, it seems untrue. April Fool’s Day appears to be a French invention, developing out of an old tradition of pranking a suitably gullible person on the first of the month, and making them a “poisson d’avril”—an “April fish.” Where this tradition derives from is unclear, but since the 1500’s at least, April 1 has been established as a prime opportunity to tease people and pull off ludicrous pranks.

Nowadays, April Fool’s Day is so well established that even newspaper headlines, broadcasters, and countless websites and online services all like to get in on the joke, and few have done so as successfully as Britain’s national broadcaster, the BBC.

The BBC has pulled numerous April Fool’s Day pranks on the unsuspecting British people over the years, including a memorable joke in 2008 in which they broadcast a news report about a colony of flying penguins discovered in the Amazon rainforest. To accompany the report, Monty Python actor Terry Jones was filmed first walking with penguins in Antarctica and then tracking their migratory flight path all the way to South America. Several years earlier, in 1989, the BBC’s flagship sports program Grandstand, which was broadcast live every Saturday morning and reported the day’s sports results as they came in, likewise pulled an April Fool’s Day prank. They had a fight appear to break out among the program’s reporters, live on air, right behind the show’s presenter, Des Lynam. (The fisticuffs were only revealed to have been a prank several hours later when the program went off air.) And in 1976, the legendary BBC broadcaster and astronomer Sir Patrick Moore was heard announcing live on BBC radio, to a dumbfounded audience of millions of listeners, that due to a unique planetary alignment between Jupiter and Pluto that day, an upward gravitational pull would be created that would temporarily make everyone on early several pounds lighter, at precisely 9:47 a.m. Despite many listeners contacting the BBC to report that they indeed felt the effects of the gravitational pull, the entire story was later revealed to be a hoax.

Of all the BBC’s pranks, however, perhaps the most famous was back in 1957.

Panorama is the name of one of the BBC’s flagship news and current affairs programs; first broadcast in the UK in 1953, it is today the longest-running news program in the world. Considered one of the most authoritative and respected news programs, each week Panorama highlights and reports on a single particularly newsworthy story, and on April 1, 1957, it broadcast a fascinating expose about spaghetti.

Swiss “spaghetti farmers,” the program explained, had successfully eradicated the “spaghetti weevil” from their plantations that year and were expecting a bumper crop of pasta. Alongside the report, Panorama broadcast footage purporting to show Swiss men and women collecting strands of spaghetti from the branches of trees and shrubs in an enormous spaghetti-tree grove. The audience watching at home were totally enthralled.

Needless to say, spaghetti was still quite an exotic food in 1950s post-war Britain, so few people watching the report would have had much idea of its true origins. As a result, having such an authoritative program, presented by an authoritative journalist, the legendary BBC journalist and political reporter Richard Dimbleby, report such “news” caught many people off guard. Even after it had been revealed as a hoax, the report continued to sucker people in, while some even contacted the BBC to ask where they could get hold of a spaghetti tree, so that they could grow their own pasta in their gardens at home. Perhaps for good reason, CNN later called Panorama’s spaghetti story, “the biggest hoax that any reputable news establishment ever pulled.”