Why is this stamp worth almost £11 million? Richard Pallot explains
At an estimated £10.7 million, the world's most valuable stamp has gone on show in London ahead of its auction in the summer.
The British Guiana One-Cent Magenta stamp is thought to be the sole survivor of its kind, created as a contingency in 1856 during a stamp shortage.
The shortage threatened to disrupt the postal service in British Guiana (now Guyana).
British Guiana commissioned a contingency supply from Britain - the one-cent black on magenta coloured paper, a four-cent magenta, and a four-cent blue.
The £10 million stamp up for grabs is the sole-surviving example of the one-cent magenta.
It was rediscovered in 1873 when L Vernon Vaughan, a 12-year-old schoolboy living with his family in British Guiana, found it among a group of family papers.
He would later sell it for several shillings to another local collector.
The stamp then entered the UK in 1878, before being sold on by a number of collectors.
It's gone up in price since then.
Its current owner, high-end shoe designer Stuart Weitzman, bought the stamp for 9.48 million dollars in 2014.
He added his own mark to the back of the stamp - inscribing his initials “SW” along with a line drawing of a stiletto shoe as a nod to his legacy in fashion.
Each of the four times it has sold at auction, the item has established a new record price for a single stamp, and is predicted to set a record at one billion times its face value.
The stamp can be viewed by the public until April 30 at Sotheby’s auction house in Mayfair.
It heads to Sotheby's in New York in a few months' time where it's expected to fetch around £7.1 million to £10.7 million at auction.