In the Middle Ages, when the Catholic Church tried to suppress all pagan ideas, it failed when it came to this celebration. The Church incorporated the rite into its own calendar as a period of thanksgiving. The nations of Europe, especially France, Spain, and Portugal, gave thanks by throwing parties, wearing masks, and dancing in the streets. All three colonizing powers carried the tradition with them to the New World, but in Brazil it landed with a difference. They would smear their faces with flour, borrow an old wig or frayed shirt of the master, and give themselves over to mad revelry for the three days.
Many masters even let their slaves roam freely during the celebration.
Since the slaves were grateful for the chance to enjoy themselves, they rarely used the occasion as a chance to run away. Of course, this normally happened just before lent. Quite how Fortaleza ended up with Fortal is a mystery, one which no one quite seems to have an answer to. In Fortal, like the main carnaval, anything goes. One year a major samba school used Leonardo da Vinci as the inspiration for its theme.