An original 1939 Keep Calm and Carry On poster could make $12,000-18,000 at Swann Auction Galleries on August 2.
These days the phrase appears as a twee slogan on T-shirts and tote bags.
Original examples of this iconic poster are extremely rare
It has also been recycled in endless tedious permutations, advertising everything from spray tans to mobile phone unlocking or advising people to "kill zombies" or "be a Belieber".
However, the original has a really good story behind it.
Following the outbreak of the second world war, the ministry of information began working on propaganda to focus the British public on the war effort.
Three posters were produced.
The first (printed in green and issued in September 1939) read: "Freedom is in Peril, Defend it With All Your Might”.
The second (in blue, October 1939): "Your Courage, Your Cheerfulness, Your Resolution, Will Bring Us Victory”.
However the last one, “Keep Calm and Carry On”, was never distributed.
It was intended to be used in the event of Nazi invasion or a horrific air attack - and it might have been used in the Blitz had the first two posters not been so unpopular.
The posters were mocked for their pomposity.
Also, not a lot of fighting actually happened until May 1940 when the Germans took France, so the message of courage in the face of adversity didn’t really connect.
The Keep Calm and Carry On posters went into the archives and most were later pulped.
Its existence was forgotten about until 2000, when one was found in a bookshop in Northumberland.
In 2014, another of these posters made $27,500 at Bonhams.
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