There is no reliable history to the group, though evidence of their existence can be found as early as the end of the First Dark Age on First Shem. Strong evidence indicates that they operated sporadically for the next few thousand years, suffering major setbacks during the rise of Terror. They operated sometimes with the Runners & sometimes co-extant with the Runners during the Age of Terror.

At the end of First Shem, their organization was known to commit pranks that benefited the sideof Hope, though some pranks failed to indicate any large scale alliance.

Though it is sometimes called the "prankster's guild", the grinning men is more of a terrorist movement split into small disconnected cells than a true organization. There are no officers, no membership roster, no rules, and no meeting schedule. Becoming a member is simply a matter of doing something so outlandish or shocking that people can only stare in awe (or horror), while leaving the image of the grinning man as the only clue to your identity.