Brazil was a colony of Portugal from the landing of Pedro Álvares Cabral in 1500 until its independence in 1822. Initially independent as the Brazilian Empire, the country has been a republic since 1889, although the bicameral legislature, now called Congress, dates back to 1824, when the first constitution was ratified Its current Constitution defines Brazil as a Federal Republic. The Federation is formed by the union of the Federal District, the Brazil is the world's tenth largest economy at market exchange rates and the ninth largest by purchasing power parity States, and the 5,564 Municipalities.