On April 1, 1572 Dutch rebels captured the town of Den Briel from Spanish troops led by Lord Alva. This military success eventually led to the independence of the Netherlands from Spain. A Dutch rhyme goes: "Op 1 april / Verloor Alva zijn Bril." This translates to: "On April 1st / Alva lost his 'glasses'". "Bril" means glasses in Dutch, but is also a pun on the name of the town, Den Briel. According to Dutch legend, the tradition of playing pranks on April 1st arose to commemorate the victory in Den Briel and humiliation of the Spanish commander.
In 1563 King Charles IX reformed the French calendar by moving the start of the year from Easter Day to January 1. His edict was passed into law by the French Parliament on Dec. 22, 1564. This aligned legal convention with what had long been the popular custom of celebrating the start of the year on January 1.
Later, in 1582, Pope Gregory issued a papal bull decreeing sweeping calendar reform, which included moving the start of the year to January 1, as well as creating a leap-year system and eliminating ten days from the month of October 1582 in order to correct the drift of the calendar. The Pope had no formal power to make governments accept this reform, but he urged Christian nations to do so. France immediately accepted the reform, since it had already instituted part of the reform (changing the start of the year) in 1564.
This sixteenth-century calendar reform is frequently cited as the origin of the custom of April Foolery. Supposedly the people who failed to realize the start of the year had been changed had pranks played on them on April 1st.
There are a number of problems with this theory. First, the start of the year was changed from Easter day, not April 1st. Second, January 1st had, since Roman times, been the traditional start of the year anyway. Easter Day had been used as the start of the year primarily for legal and administrative purposes (in an attempt by medieval rulers to christianize the calendar).
The calendar-change hypothesis is more plausible if applied to Britain, where March 25 (the date of the christian Feast of Annunciation, aka Lady Day) was New Year's Day, followed by a week of festivities culminating on April 1. However, Britain only changed the start of its calendar year to January 1 in 1752, by which time April Fool's Day was already a well-established tradition.
According to German legend, a meeting of lawmakers was supposed to occur in Augsburg on April 1, 1530 in order to consider various financial matters. Because of time considerations, the meeting did not take place. But numerous speculators, who had bet on the meeting occurring, lost their money and were ridiculed. German folklore has it that this was the origin of the custom of playing pranks on April 1.
British folklore links April Fool's Day to the town of Gotham, the legendary town of fools located in Nottinghamshire. According to legend, it was traditional in the 13th century for any road that the King placed his foot upon to become public property. So when the citizens of Gotham heard that King John (1166-1216) planned to travel through their town, they refused him entry, not wishing to lose their main road. When the King heard this, he sent soldiers to the town. But when the soldiers arrived in Gotham, they found the town full of lunatics engaged in foolish activities such as drowning fish or attempting to cage birds in roofless fences. Their foolery was all an act to make the King believe they were insane. The King fell for the ruse and declared the town too foolish to warrant punishment. Ever since then, according to legend, April Fool's Day has commemmorated their trickery. (The thumbnail shows a 1630 woodcut depicting a citizen of Gotham trying to trap a bird inside a roofless fence.)
In 1708 a correspondent wrote to the British Apollo
magazine asking, "Whence proceeds the custom of making April Fools?" The question is one that many people are still asking today. The puzzle that April Fool's Day presents to cultural historians is that it was only during the eighteenth century that detailed references to it (and curiosity about it) began to appear. But at that time, the custom was already well established throughout northern Europe and was regarded as being of great antiquity. How had the tradition been adopted by so many different European cultures without provoking more comments in the written record?