The Origins of April Fool's Day

From Wikipedia:

“A disputed association between April 1 and foolishness is in Geoffrey Chaucer's The Canterbury Tales (1392). In the 'Nun's Priest's Tale', a vain cock Chauntecleer is tricked by a fox 'on Syn March bigan thritty dayes and two.' Readers apparently understood this line to mean "32 March", i.e. April 1."

Perhaps this is true. Who is to say?

What is true is that the Tower of London once housed a menagerie or "bestiary" with a fantastic assortment of creatures, ranging from wolves, lions, and leopards to giraffes, monkeys, and tigers. The "Tiger Tower" stood for over 600 years (beginning in the 1230s), and was located where the gift shop at the Tower of London is now situated. This precursor to the London Zoo provided London residents with a glimpse of the fauna to be found in the larger world.

Among the famous who visited were Samuel Pepys, William Blake (who illustrated his poem “The Tyger" after sketching the animal from life at the Tower), and one Geoffrey Chaucer who worked at the Tower for two years (1389-1390).

A terrier features prominently in the closing of the Tiger Tower. By the early 1830s, the close quarters and poor condition of the animals kept at the Tower had become a minor issue. Exotic animals expired with some regularity. They were difficult to replace, and their death made for poor public relations. Things came to a head on April 29, 1834, when a "large and furious" wolf managed to slip out of his cage inside the Tiger Tower. The wolf immediately headed for the interior of the Tower across a short moat, but he was thwarted by a keeper - one Sergeant Cropper - who quickly shut a door to prevent the wolf from gaining further access. Cropper's small terrier, always at his side, rushed in to do battle with the wolf. The terrier quickly realized it was over-matched, however, and it raced up the stairs into Cropper's little residence where his wife and daughter were located. The wolf, of course, followed close on his heels, and the battle continued inside the apartment. Once can only be imagine the carnage and sound that ensued, but the battle interlude gave the woman and girl time to flee, though it surely cost the terrier its life. The wolf was eventually recaptured, but the Tiger Tower was closed the next year and the animals transferred to the newly opened London Zoo in Regent's Park.

In 1852, the Tiger Tower itself was destroyed, although the foundation of the "Lion Gate" remains.

This tale can be found in “The Tower Menagerie” by Daniel Hahn.

The Tower of London gift shop, where the Tower menagerie once stood.