Before it was an inescapable meme of infinite variety plastered on every crappy consumer product ever cranked out by Chinese industry, the “Keep Calm and Carry On” slogan graced a British Ministry of Information poster printed, but never used, in the early days of World War II. It was one of three poster designs in plain text bearing the crown of King George VI printed in August of 1939 to shore up the morale of the country through the confusion and fear that were sure to follow should war break out.

The other two posters — “Your Courage, Your Cheerfulness, Your Resolution Will Bring Us Victory,” and “Freedom Is in Peril Defend It with All Your Might” — were quickly distributed after Britain’s declaration of war on Germany on September 3rd, 1939. “Keep Calm,” which was intended for use in the worst case scenario of a German invasion and since that never happened, those posters were never posted. They were widely distributed as part of the preparations for war, but most of the print run of 2.5 million posters was pulped when paper shortages struck.

Never seen by the public, the poster was unknown until 2000 when one Stuart Manley, co-owner of Barter Books, a beautiful bookstore in a restored Victorian train station in Alnwick, Northumberland, found one folded in the bottom of a box of old books he’d bought at an auction. His wife Mary thought it was awesome, because it is, so she had it framed and hung it on the wall near the cash register.

Customers went gaga for it, so the Manleys made copies of the poster to sell. Soon the original was outside the shop, drawing crowds and advertising the copies for sale. When it hit the internet, the slogan spread worldwide and in short order became the meme template we know today.

For more than a decade, the Manleys’ poster was one of only two known. Then in 2012, Moragh Turnbull brought a cache of 15 of them to the Antiques Roadshow at St. Andrews University in Edinburgh. Her father William worked for the Royal Observer Corps in Edinburgh during the war and had kept many papers, including the “Keep Calm” posters that were distributed but never actually posted. The AR appraiser valued her posters at £1000.

Now, four years later, the original poster that launched a thousand dish towels will be available for purchase at the Manning Fine Art stand at the Art & Antiques Fair, Olympia in London, open now through July 3rd. According to The Guardian price tag is £21,250, but the headline says it’s up for auction so that may be the reserve set or maybe even a pre-sale estimate.