Jubilee was supposed to be a year of celebration every 100 years in which sins and debt were forgiven. In practice, Jubilees were scheduled every 25 years in order to extort money from pilgrims and the whole thing became a devious obstacle course. Four basilicas needed to be visited in order to be forgiven. Simple, right? Wrong. Romans had to make thirty visits to the four basilicas, foreigners fifteen visits. The hapless pilgrims needed to walk through a holy door in each basilica, each of wihch was unwalled by the Pope or other cardinals using a silver hammer during different days. As the wall in each door collapsed, it injured the clamouring crowd around it, who, undeterred, fought for pieces of the wall. Several hundred pilgrims were trampled to death moving between churches in 1450.
The populace was so traumatized by the insanity of the events unfolding, that performers stayed in the city for several years afterward to help ease Jubilee withdrawal.