Brazil was inhabited by numerous tribal nations prior to the landing in 1500 of explorer Pedro Álvares Cabral, who claimed the area for the Portuguese Empire. Brazil remained a Portuguese colony until 1808 when the capital of the empire was transferred from Lisbon to Rio de Janeiro. In 1815, the colony was elevated to the rank of kingdom upon the formation of the United Kingdom of Portugal, Brazil and the Algarves. Independence was achieved in 1822 with the creation of the Empire of Brazil, a unitary state governed under a constitutional monarchy and a parliamentary system. The ratification of the first constitution in 1824 led to the formation of a bicameral legislature, now called the National Congress. The country became a presidential republic in 1889 following a military coup d'état. An authoritarian military junta came to power in 1964 and ruled until 1985, after which civilian governance resumed. Brazil's current constitution, formulated in 1988, defines it as a democratic federal republic. Due to its rich culture and history, the country ranks thirteenth in the world by number of UNESCO World Heritage Sites.