Keep Calm and Carry On was a motivational poster produced by the British government in 1939 in preparation for the Second World War. The poster was intended to raise the morale of the British public, threatened with widely predicted mass air attacks on major cities. Although 2.45 million copies were printed, and although the Blitz happened, the poster was hardly ever publicly displayed and was little known until a copy was rediscovered in 2000. It has since been re-issued by a number of private companies, and has been used as the decorative theme for a range of products.
They knew only two copies of the poster in the public domain, until a collection of about 15 original were exposed in the television show Antiques Roadshow in 2012 by the daughter of a former member of the Royal Observer Corps (ROC).
As the popularity of the poster in various media has grown, innumerable parodies, imitations and co-optations have also appeared, making it a notable meme. Messages range from the cute to the overtly political, typically with references to other aspects of popular culture.
Due to its slightly irreverent sense, several parodies of the poster had been published, replacing the "Carry On" by other phrases, such as "Keep Calm and Evade the Police" or "Keep Calm and call Batman". It could also contain names of individuals, they are rapidly propagated on social networks.