There are plenty of theories as to how April Fool’s Day got started. Some say it has to do with the date in relationship to the Georgian Calendar, or to the Vernal Equinox in the northern hemisphere.
This is what Wikipedia has to say:
In Chaucer’s Canterbury Tales (1392), the “Nun’s Priest’s Tale” is set Syn March bigan thritty dayes and two.[2] Modern scholars believe that there is a copying error in the extant manuscripts and that Chaucer actually wrote, Syn March was gon.[3] Thus the passage originally meant 32 days after March, i.e. 2 May,[4] the anniversary of the engagement of King Richard II of England to Anne of Bohemia, which took place in 1381. Readers apparently misunderstood this line to mean “32 March”, i.e. April 1.[citation needed][5] In Chaucer’s tale, the vain cock Chauntecleer is tricked by a fox.
I’m going with the Chaucer theory…since cocks all over the world are still being fooled by foxes and sometimes cougars….just saying.
Here’s a list of the top 100 April Fool’s pranks of all time. http://hoaxes.org/aprilfool/
Happy April Fool’s Day!!