6 Ferdinand Waldo Demara, known as “the Great Impostor,” posed as a surgeon aboard a Canadian Navy vessel and quickly studied a textbook when he needed to perform surgery saving 16 lives. After being exposed, he was acquitted of all charges and sent back to the US. 

When the Great Depression made his father financially insolvent, 16-year-old Demara ran away to join Cistercian monks in Rhode Island. Several years later in 1941, he joined the US Army. The following year, he assumed his first fake name, deserted the Army, joined the Navy, and trained as a hospital corpsman. Later, he took the name “Robert Linton French” and taught at Gannon University in Pennsylvania as a religion-oriented psychologist. He then was an orderly in a Los Angeles sanitarium and an instructor at St. Martin’s University, Washington.

After a brief spell in prison following capture by the FBI, Demara took another fake identity to study law at Northeastern University. Then he joined the Brothers of Christian Instruction in Maine when he met Joseph C. Cyr, a young doctor. Demara soon assumed his identity and posed as a trauma surgeon on the Royal Canadian Navy destroyer HMCS Cayuga.

Demara’s most notable exploit was the surgery he performed on 16 injured combatants aboard the ship. After ordering personnel to transfer them to the operating room and prepare for surgery, he speed-read a textbook on general surgery. He operated on all of them, even performing a major chest surgery, with success. The news about one of the patients ended up in Canadian newspapers and was read by Cyr’s mother. When the ship’s captain found about about Demara, he at first did not believe it. But as it was an embarrassing situation, he dismissed Demara without pressing any charges. (source)

7 After claiming that he was made the leader of a fictional country called Poyais in Latin America, a Scottish soldier named Gregor MacGregor fooled over 500 wealthy British and French investors into buying land there. He was tried and acquitted several times by both countries. 

After serving in the British Army from 1803 to 1810, MacGregor took up the Republican side in the Venezuelan War of Independence in 1812 with great successes including a month-long fight in 1816, capturing of Amelia Island in 1817, and overseeing operations in New Granada. Upon his return to Britain in 1821, he claimed to have been made the “Cacique,” leader of an indigenous group, to Poyais by Mosquito Coasts’ King George Frederic Augustus. Though he also had many failures, interestingly, none of them were well-known, which made his claims all the more believable.

MacGregor also added a bit of flourish to his story with Josefa, the “Princess of Poyais,” who gave birth to a daughter at his sister’s home. He became increasingly popular and was invited to prominent dinners and balls including one from the Lord Mayor of London. He spun tales about a convoluted system of government, banking, military, and parliament, as well as honor systems, land titles, and coat of arms. He bequeathed titles and offices on many who in turn sold impressively designed land certificates to the public and helped organize emigrants.

MacGregor’s deception was finally revealed when of the many hundreds who emigrated only 50 survivors returned in late 1823. Some of the survivors even supported MacGregor that it was really the fault of those he put in charge of the emigration party. Though he was tried in 1826, only one of his associates was convicted. He attempted a few minor Poyais scams during the next decade and moved to Venezuela in 1838 where he was welcomed back as a hero. (source)

8 There was a self-styled physician named C.L. Blood who operated in Boston, New York City, Philadelphia, and Chicago and produced a patent medicine known as “oxygenized air.” He promoted it as a cure for catarrh, scrofula, consumption, and other respiratory tract diseases. 

Born in 1835, Blood fabricated credentials and styled himself “Dr. C. L. Blood” or “C. L. Blood, M.D.” In 1865, he came to Boston where he established an office in the old Congressional Library building and advertised his medical services. During this time he became interested in the use of laughing gas. After learning how to manufacture it, he rebranded it as “oxygenized air” and claimed it as his own invention which could cure a variety of diseases.

As he began to do well, Blood moved into better quarters and also hired accomplices to lure in investors. During the winter of 1866-67, his rival, Jerome Harris, began selling nitrous oxide under the name “super-oxygenized air,” and one of his clients’ physician was Blood. The client had a respiratory problem which caused him to froth from the mouth and contort for about an hour. Blood used this opportunity to publicize his own “oxygenized air” and made sure everyone knew how his care improved the patient’s condition. Ironically, unlike Blood, Harris was a real physician.

Blood was also involved in tax evasion, fraud against several investors, and other misdemeanors. Throughout the rest of his life, he moved to several cities setting up his “medical practice.” (source)

9 In 1770, a man invented a machine nicknamed “The Turk” which could play an exceptional game of chess against a human opponent. It wasn’t until 1857 that the machine was found to be a hoax and had a chess master hiding under it. 

Wolfgang von Kempelen was an 18th-century Hungarian author and inventor who also had a successful career as a civil servant. He once attended the court of Maria Theresa of Austria at Schönbrunn Palace where he saw an illusion act by François Pelletier. He then promised to return with to the Palace with an invention that would top all illusions.

Kempelen constructed an automaton chess-player and presented it to Maria Theresa. It consisted of a life-size model of a Turkish man who appeared to play a competent game of chess against a human opponent. For nearly 84 years, the machine played during demonstrations across Europe and the Americas, defeating many challengers including Napoleon Bonaparte and Benjamin Franklin. The interior of the machine seemed to have an intricate clockwork that misled any observer, but in fact, it concealed a human player who would operate levers to move the puppet above. (source)

10 Between 1949 and 1981, a man named Giovanni Vigliotto wooed and married 105 women in 14 countries after which he would ask them to sell their house and join him at his home far away. He would then pack all their belongings and flee to sell them at a flea market. 

Vigliotto’s antics came to a halt when his 105th wife, real estate agent Patricia Ann Gardiner, filed charges of fraud against him. Unlike his previous wives, some of whom reported the incident to investigators, Gardiner decided to find him herself. Since she met him at a flea market, she drove through all the flea markets she could find. She found him in Florida selling her furniture, and he was arrested.

Vigliotto offered to plead guilty to bigamy charges if the fraud charges were dropped. He wrote down 50 of his aliases, gave his real name as Nikolai Peruskov, and listed all the women he married with their addresses. He was tried on March 28, 1983, and was sentenced to 28 years in prison for fraud plus six years for bigamy along with a fine of $336,000. (1, 2)