According to an unlikely, but widely believed myth, the population of the northern-english coastal town of Hartlepool (pronounced Hart-lee-pool) did.

During the Napoleonic Wars, (1799-1815), a ship was wrecked near the town, and the only creature to make it ashore alive was the ship's monkey. The people of Hartlepool knew they were at war with France but had never seen a Frenchman, or a monkey before. Perhaps they had heard that the French had a different language to them, or that they were a bit hairier.

In any event, the monkey was tried for spying and found guilty. It was hanged.

As the local song has it:

The Lord Mayor of Hartlepool was walking on the shore
When he came upon a funny sight he'd never seen before
He came upon a little chap a-walking in the sand
Holding a banana in his tiny hairy hand

To this day, football teams playing Hartlepool F.C. will chant, "Who hung the monkey?". The team has a monkey mascot called "H'Angus", who in 2000, stood as a protest candidate for election as the town's mayor... and won! He has since brought the office into disrepute by attending a striptease in a pub. Classy. But he won again in 2005 anyway.

Thanks to AnotherMartini for reminding me of this: