You'd never fall for this one...

THE residents of Spiggot were a stubborn lot. While the rest of the country was busy converting to metric, inhabitants of this West Country village were refusing to change, determined instead to stick to the imperial measures they had known all their lives.

After this plucky bastion of tradition was featured in a documentary, the television studio was deluged with callers supporting their stand, with many asking to know how they could join the rebellion against encroaching decimalisation. The only drawback was it was all a hoax.

Spiggot, the non-existent village which had its moment in the limelight in 1973, joined the ranks of April Fool's Day pranks which have lived on long after the First of April has passed. From the spaghetti trees of Switzerland to the island of San Seriffe, from an iceberg towed into Sydney harbour to momentary weightlessness if you only jumped into the air, the ingenuity and reach of some of these pranks have given them a fame all of their own.

But while the arrival of the mass media meant the hoaxes achieved a renown they could not previously have managed, it does not mean that they are a recent phenomenon. Indeed, April Fool's Day has been celebrated for hundreds of years, and some of the japes did not need newspapers and television to give them currency.

Unlike many other holidays, the origins of April Fool's Day are unclear. The most widely accepted theory is that it began with the adoption of a new calendar, and dates it to 1582, in France.

Under the Julian Calendar, the New Year was celebrated on March 25, with eight days of feasting which ended on April 1, but in 1563 the Council of Trent determined that a new calendar should be introduced, named after Pope Gregory XII. In 1582, France became the first country to use Gregorian Calendar which, among other changes, moved New Year's Day to January 1.

But 16th century communications were far from instantaneous, and many people were unaware of the changes for several years, while others, like the villagers in Spiggot, many have stubbornly clung to the old ways.

As the new calendar became more accepted, those who refused to change and celebrated the New Year at the end of March were turned into figures of ridicule, labelled fools by those who had embraced the change, and made the butt of practical jokes.

One of the most popular pranks was to stick paper fish to the backs of the die-hards. The victims became known as Poisson d'Avril, or April Fish. The tradition spread to Britain, which used the Gregorian Calendar from 1752, and then to the colonies and around the world.

But not everyone subscribes to this theory. By the time New Year's Day was moved to January 1 in Britain, April Fool's Day was already a well established tradition, and there are some who feel this explanation has been designed to fit the facts, rather than being supported by any independent evidence.

Far from it being a 16th century creation, some theories trace the lineage of April Fool's Day far further back in time. Festivals involving foolery and disguise were a part of a number of different cultures. For the Romans, the winter festival of Saturnalia involved the exchange of gifts, and slaves pretended they ruled their masters, under the auspices of the Lord of Misrule, while a late March celebration involved taking on disguises.

In India, the festival of Holi in late February early March saw people throw coloured powders in the street, while the Celts honoured Lud, their god of humour, with a day of feasting.

By the Middle Ages, Saturnalia had mutated in some countries to the Feast of Fools, where a mock pope was elected to preside over celebrations. This continued into the 16th century, when it seems to have been superseded by Mardi Gras.

Mythology also provides alternative theories. One is that when Pluto, the god of the underworld, abducted Proserpina and took her into his realm, her mother Ceres roamed the earth in a fruitless search for her daughter. This may have given rise to the practice of sending someone on a fool's errand during the festival of Cerealia.

In British folklore, April Fool's Day is sometimes linked to Gotham in Nottinghamshire. It was tradition that roads travelled by the king became public thoroughfares, but in the 13th century, the inhabitants of Gotham did not want to lose their private highway and tried to stop King John from passing through. When the king sent a messenger to demand an explanation, the villagers engaged in foolish acts, such as trying to drown fish. Convinced Gotham was full of lunatics, the king decided against punishment, and bypassed the village, an event commemorated on April Fool's Day.

But evidence that April Fool's Day seems to have evolved independently in several different cultures suggests a further explanation. The arrival of spring, with its changes and surprises, may have given rise to a festival which celebrated mayhem and disorder. The Lord of Misrule was a common character in these pageants, as the normal conventions were subverted and neighbour played prank upon neighbour. April Fool's Day provided an opportunity for the populace to vent their relief at being released from winter's privations, but in a harmless way which did not threaten the established social order.

Calendar change, mythology or the changing seasons - perhaps it is only appropriate that a festival which celebrates chaos should have its roots clouded in confusion. But whatever the real explanation, only a fool would believe everything they hear on April Fool's Day.

The best, and worst, April Fools

Spaghetti Harvest

In 1957, Panorama broadcast a story on the bumper spaghetti crop enjoyed by Swiss farmers after the extermination of the feared spaghetti weevil, complete with pictures of farmers harvesting their pasta. Many viewers rang asking how they could grow their own spaghetti trees.

San Seriffe

The tenth anniversary of independence for the Indian Ocean republic of San Seriffe was commemorated in a supplement published by the Guardian in 1977. The two islands of Upper and Lower Caisse were described, as was the capital of Bodoni. Astute readers realised everything about the island was named after printing terminology.

Falling Gravity

The conjunction of Pluto with Jupiter, Patrick Moore told listeners to Radio Two in 1976, would result in a bizarre phenomenon. At 9.47am on April 1, Jupiter's gravitational pull would cancel out the Earth's, making people weightless. Anyone who jumped in the air at 9.47am would feel like they were floating. Listeners later rang in to say they had felt this floating sensation.

World Tour

To mark the 100th anniversary of Thomas Cook's first package tour, in 1972 the Times revealed that the travel agency was offering a similar deal at 1872 prices, 210 guineas, to the first 1,000 people to write to Miss Avril Foley. Thomas Cook was swamped with inquiries, the Times apologised and the reporter sacked.

Sydney Iceberg

For months, businessman Dick Smith had been promoting his plan to tow an iceberg from the Antarctic to Sydney harbour, so when it appeared on April 1, 1978, no-one was particularly surprised. They were, however, when it began to rain, and the water washed away the foam covering white plastic sheets, exposing the berg as a fake.

Prison Break

In 2000, a Romanian newspaper announced that the Baia Mare prison was going to release its inmates in a mass act of mercy. Relatives awaited the release of their loved ones, only for the newspaper to reveal it had been an April Fool's joke.

End of the World

Astronomers at the Franklin Institute in Philadelphia were predicting the world would end on April 1, 1940, according to a press release broadcast by a local radio station. A flood of panic calls was only halted when the institute said it had made no such prediction, which was traced to its press agent who wanted to promote a lecture on how the world could end.

Volcano Eruption

When smoke started billowing from the long-dormant volcano Mount Edgecumbe in Alaska in 1974, there was widespread panic. Investigations revealed a prankster had filled the crater with tyres and set them alight. When Mt St Helens erupted in 1980, the prankster received letters saying he had gone too far this time.

Operation Parallax

Years of switching the clocks over for British Summer Time had left Britain out of sync with the rest of the world, Capital Radio reported in 1979, and the solution was Operation Parallax, when April 5 and 12 would be cancelled. Calls included a woman asking what would happen to her birthday, which fell on one of the days in question.

Electric bras

Bras made out of specially treated copper interfered with television broadcasts, the Daily Mail said in 1982. According to legend, the chief engineer of British Telecom ordered female employees to disclose what type of bra they were wearing, to ensure equipment was protected.

* The Museum of Hoaxes by Alex Boese (Orion £9.99)