Roots of April fools day are not known to this day, though there are some variations from where it stems. For example, it might be the April 1st in 1698 when many Londoners were tricked into coming to see "the Lions washed." It also might be as early 1381, when Geoffrey Chaucer's The Canterbury Tales were published, in which a depiction of Chauntecleer tricked by a fox took place on April the 1st. It doesn't really matter where this tradition comes from since it has gained worldwide popularity and gave us a chance to laugh with April fools pranks.