The Portuguese were the first European settlers to arrive in Brazil in 1500 led by Pedro Cabral, beginning the colonial period. They found an estimated 7 million native Indians living in the area in temporary dwellings or villages of up to 5,000 inhabitants with limited agriculture. Archaeological evidence shows humans have been in Brazil for at least 50,000 years, with the Tupi-Guarani being the most populous indigenous group. Portugal exploited Brazil's natural resources from the 15th century onward as part of European commercial expansion, establishing sugar plantations and mining operations using slave labor. Brazil gained independence from Portugal in 1822 and became a republic in 1889, though the military took control intermittently until civilian rule was restored in