It was one of the most audacious cons of the 19th century, and it worked not once, but three times.

Nick Morrison reports on the remarkable story of the adventurer who became the Prince of Poyais and made a career out of selling a dream.

IT sounded like paradise on earth. Rich, fertile soil and luxuriant green forests, surrounded on one side by tropical seas filled with abundant marine life, and on the other by a chain of virtually impassable mountains, making it all but impregnable to invaders. As if that were not all, scattered through those mountains were gold mines which had been left largely undisturbed.

Perhaps most alluring of all for wary Europeans was the capital, St Joseph, a thriving and sophisticated city, whose wide boulevards and majestic government buildings gave it something of the feel of Paris.

If there were to be any grounds for caution it would be in the behaviour of the natives. Many an attempt to settle a new land had come undone at the hands of hostility from ungodly savages. But here, again, Poyais was not to be found wanting. Not only were the natives civilised after more than a century of contact with the British, but their king had appointed a Scotsman as governor. Sir Gregor MacGregor, veteran of the Napoleonic Wars, went by the title His Highness Gregor, Cazique - or Prince - of Poyais.

And it was His Highness himself who had travelled over to Britain, with the sole purpose of recruiting Europeans to settle in Poyais. Looking for those with a sense of adventure and the skills to exploit and develop a country of abundant natural resources, the Cazique dangled the opportunity to be among the first colonists of this promised land in front of a salivating public.

In the end, some 320 people took up the offer, and set sail on the Kennersley Castle from Leith, Edinburgh, on Wednesday, January 22, 1823. Eight weeks later, late in the afternoon on March 20, they dropped anchor at the entrance to a lagoon in the Sea of Poyais, and prepared for the morning, when a pilot boat would come to take them into port. The colonists could barely contain their excitement as they ate what they imagined would be their last meal on board ship, all eager to start their new life in Poyais. The only hitch was that Poyais didn't exist.

There was no fertile soil; there were no gold mines; there was no city of St Joseph, much less any tree-lined boulevards; there was no fledgling government, there were no natives eager to embrace Western civilisation, and there was no king.

Instead, there was unbearable humidity, dangerous swamps, no fresh water and mosquitoes everywhere. This wasn't what it said in the brochure.

Poyais was born in the imagination of Gregor MacGregor, and existed only in the minds of those he had duped. A smooth-talking adventurer, soldier of fortune and social climber, MacGregor had pulled off one of the most audacious frauds in history, made all the more incredible by the fact that he went on to repeat it twice more, even when he had been unmasked as a conman.

The extraordinary story has been pieced together by a former journalist with The Northern Echo, David Sinclair, the result of hours poring over documents in the British Library and the National Library of Scotland, tracking down contemporary accounts, as well as an enormous piece of luck, when he came across a guidebook to Poyais published by MacGregor in 1822, in a second-hand booksellers. The guidebook, used by MacGregor to entice would-be investors and settlers, was the only one in circulation.

"It is probably one of the best organised frauds in history," says Mr Sinclair, a former pupil of Darlington's Queen Elizabeth Grammar School. "When I first heard it, I thought it was an apocryphal tale, but it turns out to have been incredibly well-planned. I have never come across a story like this."

MacGregor, a descendant of Rob Roy MacGregor, joined the British Army and rose to the rank of captain, marrying a wealthy woman in the process, but was kicked out after getting into an argument with a senior officer. It was then that his capacity for self-invention seems to have made itself evident.

Perhaps driven by a desire to improve his social status, he announced he was now Sir Gregor MacGregor, chief of the clan MacGregor and related to most of the aristocratic families in England. It may have been completely untrue, but it worked, and he swiftly became accepted in the most desirable social circles.

Then his wife had the temerity to fall ill and die and, blocked from taking up her fortune by her suspicious relatives, MacGregor was forced to seek his fortune elsewhere, and headed for Latin America, where he became a mercenary, passing himself off as a hero of the Napoleonic Wars, without having fought in them at all.

And it was his experience in Central and South America which provided the inspiration for his fraud. On his return to Britain in 1821, he announced he was the Cazique of Poyais, in London for the coronation of George IV, and full of tales of his wonderful homeland.

Despite no one ever having heard of Poyais up to that point, this prince of an exotic-sounding land became the talk of the city, feted by the Lord Mayor and accredited to the Court of St James. From there, it was but a short step to setting up an office to sell land in Poyais, and encouraging people to start a new life, all supported by documents, certificates and a guide book.

Eventually the interest was so great, MacGregor was forced to charter ships to take the settlers to Poyais, located on the coast of Central America, between modern-day Honduras and Nicaragua. It had indeed once been the site of a British colony, but it was abandoned in the 18th century, and the land was so dismal the Spanish had not bothered to settle there.

When the passengers on board the Kennersley Castle arrived, they could see why it was uninhabited. Once their plight became known, an expedition was despatched from nearby Belize to rescue them, but by then many had succumbed to disease. Of the 320 who left Leith, only 50 ever returned.

But amazingly, this did not lead to MacGregor's exposure as a fraud. So completely had the public bought into his dream, that it was assumed the colonists had landed in the wrong place. One of them even wrote a book defending MacGregor, saying it was not his fault.

MacGregor moved to Paris, and tried the same thing again, but when French bureaucrats, startled by the flood of applications for passports to visit Poyais, found there was no such place on their maps, the self-styled Cazique was arrested, tried and found guilty, escaping jail only on the condition he left France.

Undaunted, MacGregor returned to London and started selling land in Poyais again. Even more surprisingly, people started buying it.

"It is amazing that people can be so gullible, but his marketing was incredible," says Mr Sinclair. "He had engravings done which were circulated on the street, and it was also a very optimistic time: the Napoleonic Wars had finished and people were looking for something to do.

"He was so convincing and people believed in his fantasy. You see time and time again that people are quite easily parted from their money if they think they are going to make a tidy profit.

"In some ways, he wasn't a straight-forward conman - he was a fantasist and that helped to convince other people. Underneath it all, I think he was not a very nice man, but he must have been brilliant in his own way, and he would have been marvellous company."

How much MacGregor made from his scams is not known, although Mr Sinclair reckons it was several hundred thousand pounds. But the cost of setting up the fraud and a collapse in the South American bond market meant his profits were nowhere near as high as he hoped.

Eventually, MacGregor retired to Scotland but when his money ran out he returned to South Am erica, trading on his earlier mercenary exploits, but with his fellow soldiers dead he was able to embellish his adventures and paint himself as a hero of the continent's liberation from the Spaniards. When he died, in 1845, the President of Venezuela marched behind his coffin, and his contribution, much of it his own invention, is marked by a memorial in the cathedral in Caracas.

But the story did not end with MacGregor's passing. Even 20 years after his death, stories of the fabled land of Poyais were still circulating. Even then, there were those prepared to hand over money for the land that never was.

* Sir Gregor MacGregor and the Land that Never Was by David Sinclair, is published by review (£16.99).