Paul Whiting, 71, of Hounslow in west London, was sentenced at Swindon Crown Court this month after he stole thousands of pounds worth of paintings and antique books from art galleries, book dealers and an auction house.
He committed his crimes between June and October last year and pleaded guilty to six counts of theft in court.
The pictures stolen included a portrait of Pope Innocent X, valued between £3000 and £5000, which was stolen during a pre-sale viewing at an auction house in Kensington.
He had then taken it to a west London gallery and sold it for £70.
“Prolific and determined thief”
The theft was uncovered after an employee of the gallery took the painting to be valued at Christie's on November 1, where it was recognised as a stolen painting.
The gallery returned the stolen painting to the auction house and an investigation was launched by Metropolitan Police's Art and Antiques Unit.
Working together with the gallery, the police identified 17 further items that Whiting had offered for sale.
Whiting was arrested at his home address in November 2016 and he told officers he had committed the offences to "make ends meet".
Detective Constable Sophie Hayes, of the Metropolitan Police's Art and Antiques Unit, said: “Paul Whiting is a prolific and determined thief who stole from international institutions and small businesses alike. We were pleased to be able to identify the owners of some stolen property, however we are still working to identify the owners of other seized property.”
Hayes gave thanks to the Antiquarian Booksellers Association (ABA) which alerted book dealers to Whiting's suspicious activities and helped the police to identify owners of stolen property.
The police is still trying to identify a number of works including a bronze sculpture and a pointillism painting.