Brazil's indigenous cultures employed masks long before Carnival made the country famous for them. They are most often seen at the tourist-attracting celebration.
Masks in Indigenous Cultures
Indigenous cultures have been employing handmade fiber masks for unknown centuries to tell important cultural legends, like those of earth's creation and floods.
Origin of Carnival Masks
The famous Brazilian Carnival celebration did not start in Brazil at all; it began in Europe. When the Roman Catholic Church attempted to ban all pagan rituals, they failed to banish all of them, including a wild spring celebration Europeans immigrating to Brazil in 15th century brought with them. It involved wearing masks, throwing parties and dancing in the streets.
Carnival temporarily (albeit unofficially) suspends most rules of law and society. The highlight of Carnival until the 1840s was pranking, and wearing masks allowed celebrators to do it anonymously.
Masks and Slaves
Masks also allowed slaves to participate in Carnival's celebrations anonymously. Slaves made the plain white mask famous by covering their faces in white flour and taking part in the festivities. This, too--unlike at any other time during the year--was allowed.
Masks hit their most globally famous form in 1840, when a wife of an Italian hotel owner threw a lavish masked ball, complete with expensive invitations, musicians, and imported party supplies like confetti and streamers. These masked balls replaced pranking as the highlight of Carnival.