Which public-service campaign used the slogan “Keep Calm and Carry On”?

The British government used the slogan “Keep Calm and Carry On” in a 1939 wartime poster campaign.

The poster was designed by the British Ministry of Information before the Second World War as part of a series intended to maintain public morale during the expected disruption of enemy attack. It used a simple crown at the top and large, direct lettering. Unlike two related posters, “Your Courage, Your Cheerfulness, Your Resolution Will Bring Us Victory” and “Freedom Is in Peril,” it was not widely displayed at the time because the feared invasion and mass bombing conditions developed differently than anticipated.

The design became famous decades later after an original copy was discovered in a second-hand bookshop in Alnwick, England. Reproductions then spread through shops and the internet. Modern versions often parody or adapt the wording, but the original slogan belongs to the British government’s wartime Ministry of Information.