Located just 14 miles from central London, Passingford Bridge in Essex is a solitary spot.

If you're driving from Woodford or Romford on the road to Ongar, there's nowhere to park and nothing much to see when you cross the River Roding.

The name seems appropriate – Passingford Bridge.

But the modern name is only 200 years old.

"For 600 years before 1819, Passingford Bridge was spelt not with an A but with an I," said retired history professor Ged Martin, who has studied its embarrassing history from his home in Ireland.

Travellers were originally guided to safe crossing point by a large marker post.

"The Anglo-Saxon word for a post was 'stapol'." explained Professor Martin.

"Hence the name of the two parishes on either side, Stapleford Abbotts and Stapleford Tawney."

"But during the Middle Ages, the crossing got a nickname. It was first recorded in 1224 as 'Pyssingford'. From 1297, it was Pissingford Bridge."

Ged Martin has traced around 60 mentions over 600 years.

He believes the strange name resulted from the construction of a watermill about half a mile upstream.

It is mentioned in Domesday Book, so it was built before 1086.

"The fall of water on the Roding is about four feet per mile," he explained.

"Creating a head of water to turn a waterwheel meant digging an artificial channel to create a mill dam."

"The water flowed back to the Roding through a narrow mill race, rejoining the river about 500 yards above Pissingford."

Professor Martin thinks the river was usually low anyway in late summer, around harvest time.

He said: "Surges of water from the mill frothed over the shallow ford, triggering its strange name.

"17th and 18th century London had at least 3 Pissing Alleys, plus a water fountain called the Pissing Conduit near St Paul's Cathedral.

"Even Shakespeare mentioned it.

"There was a Pissing Gutter at Coggeshall in Essex, and a Pissing Stone near Maidstone.

"Dr Samuel Johnson was careful to omit other 4-letter words from his famous 1755 Dictionary, but he included 'piss' both as a noun and a verb, complete with an illustrative couplet from the poet Dryden."

The first major history of Essex, published in 1768, had no problems with Pissingford – and its author, Philip Morant, was a clergyman.

But the old name was on borrowed time.

Professor Martin added" "Around 1800, a new watermill was built just downstream from the bridge, damming the river. The Roding now formed a lake, swamping the original ford."

And Britain was entering an age of narrow-minded politeness.

"Even words like 'sweat' and 'belly' became shocking," he said.

"It wasn't long before men washed their hands and ladies powdered their noses.

"But the old name hung on another 20 years in darkest Essex."

It was replaced by Passingford Bridge around 1819 – at just the time Jane Austen was writing her well-mannered novels.

Professor Martin thinks local gentry and clergy must have leaned on mapmakers and travel publishers to clean up their act.

Amazingly, no trace of their influence survives.

"That's how we do things in Britain," he joked.

"Powerful people have a quiet word in the right quarters, and get what they want."

In recent years the Internet has dragged Pissingford back from the shadows of history.

"The Essex Record Office lists the documents it holds on its website, revealing over 30 examples of the embarrassing name," he said.

"Search engines turn up the rest through old maps and travel books."

The site of the original Domesday watermill is now under the M25, but the cut for the mill race can be seen on Google Earth.

The watermill downstream stopped working decades ago, but the buildings are still there.

And the deep, placid Roding makes Passingford Bridge a favourite place for anglers.

To read more go to www.gedmartin.net/martinalia-mainmenu-3/300-pissingford-an-embarrassing-essex-place-name-2