During the military dictatorship in Brazil, MR8 was formed by Brazilian Communist Party members who disagreed with the party's decision not to take part in armed resistance against the military government, the so-called Dissidência da Guanabara. The name Movimento Revolucionário 8 de Outubro was taken from another organization, recently destroyed by police repression. Dictatorship propaganda boasted of police effectiveness in suppressing of "terrorists," so the DI-GB began using the same name to demoralize the regime. The new organization defined itself as Marxist-Leninist and was the main force behind the kidnapping of AmericanambassadorCharles Burke Elbrick in 1969, which was later the basis for the film Four Daysin September. In the late 1970s, MR8 conducted thorough autocriticism for its participation in armed resistance against the dictatorship. Under the leadership of Daniel Terra, it defined the struggle for "democratic liberties" as the primary task for the Brazilian left and became active inside the MDB, the party of the "allowed opposition," under Orestes Quércia, and had an important role in the reawakening of the student movement in 1976-1977. However, It came to believe that the "national issue" was more important than the "democratic issue" and in 1978 shifted its policies. It never abandoned the struggle against the dictatorship, but became increasingly aggressive against other leftist movements, particularly the Trotskyists, frequently seen as antinational and supportive of "petty-bourgeois issues" like feminism, environmentalism, and gay rights. The MR-8 became increasingly isolated within the left, prompting alliances among other leftist movements against it. While MR8 played an important role in the 1977 student movement, when the working class and unions came again into political play in 1978, the MR-8's role was marginal or frequently even negative. It developed an intense political enmity towards the unionist leadership of the ABC Region, which later gave birth to the Workers' Party. Luiz Inácio Lula da Silva and other leaders of the party and its union branch, the Central Única dos Trabalhadores, were described as social-democrats, yellow unionists and imperialist agents, and accused of dividing the opposition against the dictatorship, the MDB. With the end of the dictatorship, it was the only significant part of the Brazilian left to remain within the PMDB, the continuation of the MDB. Most other groups joined the PT while the Brazilian Communist Party and the Communist Party of Brazil relaunched themselves as independent political parties. The MR8 is a bit of an oddity in Brazilian politics, as it considers itself "Marxist-Leninist" but is not organized under democratic centralism and operates within a bourgeois centre-to-left political party, in direct contradiction to the Marxist-Leninist tenets of independence from bourgeois organizations. In the late 1990s, MR8 became somewhat reformist like other leftist movements and a more moderate socialist group. It even supporting Lula's successful run for presidency in 2002 and later his government as well. At the same time, it increased its nationalist streak. It publishes a twice-weekly newspaper, Hora do Povo.
In 2008, it decided that the great changes in Brazil made it time for it to change. On April 21, 2009, it launched the Free Homeland Party, which is now registered.
