[PzLdr]

Actually, it's true. During the siege of Vienna, a baker within the city walls heard the sounds of Turkish troops undermining the walls [they'd dig tunnels and/or place gunpowder under a wall section to collapse it]. The baker notified the defenders, who launched a counter mining operation and saved the wall. For his deed, the baker was given the exclusive right to make a product to commemorate his deed - what is now called a croissant - made in the shape of the Turkish [and Islamic] crescent.

[paudio]

Thank you for a richer description of what happened.