Sotheby’s, which will be exhibiting at a treasure auction on December 7, said it was dated 1840 and is “the oldest model of the first known postage stamp”.
The sticker, which bore a profile of Queen Victoria’s face and cost a penny at the time, is attached to a document dated 10 April 1840 from the archives of Robert Wallace, a Scottish politician who reformed the British Postal Service.
The stamp has been offered at a flat rate since May 8, 1840, before that postage was paid by the recipient.
“This is the first ever postage stamp, a precursor to all stamps, and undisputedly the most important piece in philatelic history,” Sotheby’s Treasure Sales Manager Henry House said in a statement.
The stamp is one of three black-brown stamps believed to have survived from the first printed edition, and the other two are in the British Postal Museum’s collection.
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