By Rosa Hodgkin
In 1708 the Apollo Magazine printed the query, “Whence proceeds the custom of making April Fools?”. The answer received was
“It may not improperly be derived from a memorable transaction happening between the Romans and Sabines, mentioned by Dionysius, which was thus: the Romans, about the infancy of the city, wanting wives, and finding they could not obtain the neighbouring women by their peaceable addresses, resolved to make use of a stratagem; and accordingly Romulus instituted certain games, to be performed in the beginning of April (according to the Roman Calendar), in honour of Neptune. Upon notice thereof, the bordering inhabitants, with their whole families, flocked to Rome to see this mighty celebration, where the Romans seized upon a great number of the Sabine virgins, and ravished them, which imposition we suppose may be the foundation of this foolish custom.” 
People still seem to be curious about the origins of April Fools’ Day, but few clear answers have been found. Chaucer’s 1392 story The Nun’s Priest’s Tale is often cited as the first mention of April Fool’s Day. In the story a rooster is fooled by a fox and is almost eaten. Chaucer describes this tale as taking place:
When that the monthe in which the world bigan
That highte March, whan God first maked man,
Was complet, and passed were also
Syn March bigan thritty dayes and two. 
People have argued this refers to 32 days after the start of March, i.e. the 1st of April and so is the first reference to fooling people on that day. However, many researchers think this was a scribal error and it actually referred to 32 days after the end of March or May 2nd. Some have suggested that the scribal error is evidence that the scribe was familiar with the custom of playing tricks on the 1st of April but there is no evidence for this. 
Two more plausible references have been identified in the 16th century. The first is in a 1508 poem called Le Livre de la Deablerie (The Book of Devilry) by Eloy D’Amerval which refers to the ‘poisson d’Avril’ which is the French April Fools’ Day tradition, where children try to stick paper fish on adults and the person fooled is called the ‘poisson d’Avril’ or ‘April Fish’.  This is argued to have come from the idea that fish are easiest to catch in April – they are foolish fish. It’s not clear if this mention refers to April Fools’ Day or just a foolish person however. A clearer mention is a 1561 Flemish poem by Eduard de Dene where a nobleman sends his servant out on fool’s errands and the servant worries that the errands are nothing more than an April 1st joke.  This appears to be reasonably firm evidence that the custom of playing practical jokes on the 1st of April was present in Northern Europe as early as the 16th century.
Sending people on fool’s errands has been a persistent part of April Fools’ celebrations. ‘Hunting the gowk’ was the tradition in Scotland, where people were sent to deliver a message which told the recipient to send them off again with another pointless delivery. 
Mentions of April Fools’ Day appear more frequently from the seventeenth century. In a 1686 book the antiquary John Aubrey states about ‘Fooles holy day’: ‘We observe it on the first of April … And so it is kept in Germany everywhere’. A London newspaper apparently reported on April 2nd 1698 that several people had been tricked into going to the Tower of London to see the non-existent washing of the lions ceremony, a prank that continued into the mid-1800s. By the eighteenth century the tradition of fooling people on April 1st seems to have been well established in Northern Europe.
The modern tradition of fake news stories on April Fools’ Day seems to be a later addition, starting to appear in the late-nineteenth and early-twentieth century. In 1878, the New York Daily Graphic reported that Thomas Edison had created a machine that could turn water into wine and earth into food, while in 1905 the Berliner Tageblatt reported that all the reserves of the US Federal Treasury had been stolen. The most famous of these was of course the 1957 BBC spaghetti hoax, where it convinced a sizeable part of the British population that spaghetti grew on trees.
One of the most common theories about the origins of April Fools’ Day is that it dates from the transition from the Julian to the Gregorian calendar in France in 1582. This meant the new year transition moved from Easter to January 1st. The story is that people who couldn’t make the transition and still celebrated the new year at Easter were fools. However, this seems an unlikely explanation as the transition to celebrating New Year on January 1st was less abrupt and more organic than this narrative suggests, and as discussed earlier there seem to be references to April Fools’ Day before 1582.
More intuitively, but with no solid evidence, people have drawn connections with ancient festivals of hilarity, disorder and reversals that occurred between the Winter and Spring equinoxes like Hilaria, a Roman holiday celebrated on the 25th of March, Saturnalia, another Roman festival in December, the Indian festival of Holi and the British Hocktide festivities. It is often also associated with the Medieval Feast of Fools, but a recent book has argued that this holiday was not, as is commonly believed, a raucous festival of reversals, but instead purely liturgical and celebrated only by religious orders.
What seems clear is that April Fools’ Day dates back around 500 years and if its origins were ever definitely known they had been forgotten within a couple of hundred years of its first appearance in Northern European communities. It is perhaps appropriate that researching the history of April Fools’ Day can feel like a fool’s errand.
 John Brand, Henry Ellis, and William Carew Hazlitt, Brand’s Popular Antiquities of Great Britain. Faiths and Folklore; a Dictionary of National Beliefs, Superstitions and Popular Customs, Past and Current, with Their Classical and Foreign Analogues, Described and Illustrated (London: Reeves and Turner, 1905)., 13.
 For example: Jo-Anne Rowney, “Happy April Fools’ Day 2017! What Is the Origin Behind It, Top Facts, Best Pranks and Why We Celebrate the Tradition,” Mirror, 1 April 2017 http://www.mirror.co.uk/news/uk-news/happy-april-fools-day-2017-10134178; Amy Willis, “The Historical Reason We Celebrate April Fools Day with Pranks,” Metro, 1 April 2017 http://metro.co.uk/2017/04/01/the-historical-reason-we-celebrate-april-fools-day-with-pranks-6531125/.
 Geoffrey Chaucer, John H. Fisher, and Mark Allen, The Complete Poetry and Prose of Geoffrey Chaucer, 3rd ed. (Boston: Wadsworth, 2011), 306[3186-3190].
 Peter W. Travis, ‘Chaucer’s Chronographiae, the Confounded Reader, and Fourteenth-Century Measurements of Time,’ in Constructions of Time in the Late Middle Ages ed. Carol Poster and Richard J. Utz (Evanston, Ill.: Evanston, Ill. : Northwestern University Press, 1997., 1997), 22-26; Stephen Winick, “April Fools: The Roots of an International Tradition,” Library of Congress, March 28 2016.
 Éloy d’ Amerval, Le Livre De La Deablerie (1508).
 Eduard de Dene, Testament Rhetoricael (1561).
 Christina Hole, A Dictionary of British Folk Customs (Oxford: Helicon, 1995), 26.
 John Aubrey, Remaines of Gentilisme and Judaisme, ed. James Britten (London: W. Satchell, Peyton, and Co., 1881), 10.
 Hole, A Dictionary of British Folk Customs, 26; Robert Chambers, The Book of Days : A Miscellany of Popular Antiquities in Connection with the Calendar, Including Anecdote, Biography & History, Curiosities of Literature, and Oddities of Human Life and Character (London: W&R Chambers, 1869), 461-462.
 ‘A Food Creator. Edison Invents a Machine That Will Feed the Human Race,’ The Daily Graphic, 1 April 1878; ‘Der Milliardenraub Im Bundesschatzamt,’ Berliner Tageblatt, 1 April 1905, 6.
 Arthur Augustus Tilley, The Literature of the French Renaissance, vol. 1 (Cambridge: Cambridge University Press, 1904), 268.
 Hole, A Dictionary of British Folk Customs, 25-27, 144-148.
 Max Harris, Sacred Folly : A New History of the Feast of Fools (Ithaca N.Y.: Cornell University Press, 2011).
Image: Public domain under Creative Commons, via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Washing_of_the_Lions.jpg.