02/24/2012 02:47 pm ET Updated Oct 11, 2012

Antiques Roadshow: Only Originals Of 'Keep Calm And Carry On' Posters Discovered In The U.K.

Though you've seen this slogan on everything from mugs to notebooks, you might not know that it dates back to a 1940s poster. Now, a set of 15 of the originals, which could possibly be the only remaining ones in the world, has been discovered on the U.K. version of Antiques Roadshow.

What's the fuss, you may ask. The posters were originally part of a series created by The Ministry of Information to help boost morale around England during WWII. 'Keep Calm And Carry On' was the third motivational slogan that was to be turned into posters in the event that Britain was invaded by Germany. Since that never happened, the posters never saw the light of day. All of the Keep Calm posters were believed to have been destroyed until a bookseller uncovered one and brought it to the public eye several years ago. (And since then, has been a bit inescapable in the design realm.)

As for the newly surfaced Keep Calm originals, the owner of the posters turns out to be the daughter of a man who used to serve in the Royal Observer Corps defense organization. To find out more about this collection of posters and the backstory, read this article.

What do you think of these posters? Do you think it's an authentic set? Let us know in comments below.

For our U.K. readers: This episode of Antiques Roadshow is slated to air on BBC One this Sunday, February 26.

Also, watch the video below from the U.S. version of Antiques Roadshow about finding treasures in the most unexpected places.