Michael Hammond, 36, who once caused three innocent men to be searched at gunpoint after he claimed he had seen one carrying a pistol near Downing Street, was told he had put lives at risk with his actions.
The fantasist called police 133 times in an 11-month period between September 2003 and last August. He was caught after he tricked his way into Windsor Castle by pretending to be a detective escorting a friend of Prince William and Prince Harry.
The security breach was only spotted after Hammond and a girlfriend had spent more than an hour walking around the grounds in May last year.
Although no members of the Royal Family were in at the time, the escapade exposed fresh failings in security at the castle. It came just 12 days after the completion of a review of royal security ordered after a "comedy terrorist" gatecrashed Prince William's 21st birthday party at the castle in 2003.
Isleworth Crown Court in west London heard the incident in May last year was one of dozens of deceptions carried out by the heavily-indebted decorator's son.
The fast-talking fraudster had been a regular on London's party circuit, where he falsely boasted of love affairs with famous women and claimed to be friends with Prince Charles. His photograph appeared regularly in newspaper gossip columns as a "film consultant" and "Brit smoothie".
The court was told Hammond also had a penchant for claiming the identities of serving Metropolitan Police officers and causing innocent people to be searched.
In one incident, he pretended to be a Scotland Yard detective investigating black-on-black gun crime who had seen three men, one with a hand gun, acting suspiciously at a McDonald's near Downing Street.
Armed officers and a diplomatic protection unit were rushed to the scene and the men were held at gunpoint before being released.
On another occasion, Hammond caused an Iraqi family travelling on a ferry to Dover to be detained after claiming he was a detective who had recognised them on an Interpol watchlist of al-Qa'ida suspects.
Judge Richard McGregor-Johnson, sentencing the conman, said: "You caused police officers, including armed officers, to stop and search innocent people. Quite apart from the stress and fear that must have caused those people, you created the risk of something much worse.
"You could not possibly know how those being searched would behave or react ... and producing loaded weapons in such circumstances inevitably carries with it the risk that an action or reaction could be misunderstood with tragic consequences."
The tall, dark-haired defendant, affected indifference as he was told there was nothing to indicate he had acted on impulse and that his tally of false phone calls to police had no equal in court records.
The court was told that in February last year, he called City of London Police pretending to be a surgeon in need of a escort convoy as he rushed to perform a life-saving operation.
Hammond, from Cubitt Town, east London, even phoned the next day to thank the officers who helped him and said the "surgery" he performed had been a success.Reuse content