The first government of Brazil included a monarchy
Brazil . 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 .