At least 15,000 protesters wearing the red shirts, the Brazil's landless movement, have gathered around the Congress in the country's capital Brasilia.
By the Late Republic, these institutions were challenged by increasingly powerful Roman generals, who controlled large armies drawn from the landless poor.
Non-governmental organizations say the number of landless activists killed over the past years has fallen but that the number of death threats issued against them has almost tripled.
This decree made it functionally impossible for native Africans to own land, shattering the system of collective tribal ownership and creating a class of landless people.
The overwhelming majority of the manual work was done by landless black labourers, the descendants of the Khoisan who had been stripped of their ancestral lands under Dutch rule.