With the arrival of Longitude Prize, we look back through the history of challenge prizes, from the genius of John Harrison and his marine chronometer, to the bravery of Charles Lindbergh's first cross-atlantic flight.
These ten examples cover a diverse range of moments in history when a challenge prize has been created to inspire a solution to a problem. They don't always work, and not all of the ideas are perfect, but they all demonstrate important attempts to change things for the better.
Ever wondered how margarine was invented? Or how the concept of canning was discovered? Of course not, but here's your chance to find out regardless!
Discover more about these prizes below and visit our Challenge Prize Centre.