LONDON (Reuters Life!) - The world's oldest recorded joke has been traced back to 1900 BC and suggests that toilet humour was as popular with the ancients as it is today.

It is a saying of the Sumerians, who lived in what is now southern Iraq and goes: "Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap."

It heads the world's oldest top 10 joke list published by the University of Wolverhampton on Thursday.

A 1600 BC gag about a pharaoh, said to be King Snofru, comes second -- "How do you entertain a bored pharaoh? You sail a boatload of young women dressed only in fishing nets down the Nile and urge the pharaoh to go catch a fish."

The oldest British joke dates back to the 10th Century and reveals the bawdy face of the Anglo-Saxons -- "What hangs at a man's thigh and wants to poke the hole that it's often poked before? Answer: A key."

"Jokes have varied over the years, with some taking the question and answer format while others are witty proverbs or riddles," said the report's writer Dr Paul McDonald, senior lecturer at the university.

"What they all share however, is a willingness to deal with taboos and a degree of rebellion. Modern puns, Essex girl jokes and toilet humour can all be traced back to the very earliest jokes identified in this research."

The study was commissioned by television channel Dave. The top 10 oldest jokes can be viewed at www.dave-tv.co.uk.