One of the most successful con men of all time was the Scotsman Gregor MacGregor (1786-1845).
Among his most successful and notorious scams was to encourage investment in the fictional country of Poyais. Allegedly located near modern-day Honduras, Poyais was held out to be rich in natural resources but short on cash to develop them. MacGregor claimed that he was the cacique (prince) of Poyais, authorized to sell bonds on behalf of the government.
Over his lifetime, he scammed £1.3 million in the bond market (the equivalent of $5.6 billion in 2014 US currency).