In the 1940s and 50s, families from Maranhão, the Piauí interior and the Bahian sertão pushed into the mid-north of Goiás, part of the great westward migration the federal government had been encouraging for years. They cleared plots, planted rice and beans, and built houses. What they did not have was documentation, which made them posseiros — occupants with a claim by use rather than by deed. Into that gap came the grileiros, land grabbers who manufactured titles to enormous tracts and then sent men with guns to enforce them. The method was consistent: burn the house, destroy the crop, drive the family off, repeat. José Porfírio arrived in the region in the late 1940s. In 1954, not long after his wife died, gunmen burned his place. He did not leave.

What happened next is what makes Trombas and Formoso unusual. Rather than scattering, the posseiros organised. Militants of the Brazilian Communist Party reached the area around 1954 and helped build a structure, but the shape of it came from the land itself: the peasants formed councils along each córrego, each watercourse, so that every cluster of families along a stream had a body that argued out its own problems, decided its own share of the strategy, and organised its own defence against police raids and hired gunmen. Above them sat the Association of Agricultural Workers of Trombas and Formoso, with Porfírio elected as its first president. Between 1954 and 1957 the conflict reached its peak. State authority effectively withdrew, and the association governed in its place — outsiders started calling the area the free republic of Trombas and Formoso, which was partly a joke and largely accurate.

The extraordinary part is that they won. In 1961 the Goiás government under Mauro Borges, unable to dislodge the movement and facing an organisation too disciplined to simply repress, changed approach and began regularising the occupied land. Surveyors went out. Boundaries were drawn. On 18 August 1962 the governor came in person to Formoso to hand over the first 129 property titles, and was received as a hero; by the end of the process some 20,000 titles had gone to posseiros across the region. Later that year Porfírio ran for state deputy on a PTB ticket and took 4,663 votes — the first time in Brazilian history a peasant reached that office. He kept his distance from the governor's politics all the same. The point had never been patronage. The point was paper.

The military seized power on 1 April 1964, and the reckoning was quick. Porfírio's mandate was annulled on 1 June by President Castelo Branco. The association was dissolved. Leaders were hunted, jailed and in some cases killed; Brazil's National Truth Commission later documented that the repression in Trombas and Formoso reached the peasants' children as well as the adults. Thousands of families left the region altogether. Porfírio himself was tracked down and arrested in Riachão, in Maranhão, then held, released, rearrested, and finally taken to DOI-CODI before vanishing in 1973. He is officially a disappeared political prisoner. The land titles, at least, held — which is not nothing, and was more than most Brazilian peasant movements of that decade had to show.

Trombas became a district of Formoso in 1968 and a municipality in its own right by state law 10,436 of 9 January 1988. It is a small place in the extreme north of Goiás, 424 kilometres from Goiânia by a chain of highways, hemmed in by Montividiu do Norte, Formoso, Campinorte, Campinaçu, Minaçu, Santa Tereza de Goiás and Porangatu. Around 3,500 people lived here in 2007, roughly two-thirds of them in town, at a density of under five per square kilometre; the population has been falling since 1991. Cattle dominate — some 46,700 head — with rice, corn and soy on modest acreages, four schools, one hospital with fifteen beds, and a human development index of 0.743 that puts it in the middle of the state. Nothing about the place announces its history. The archive of it now lives at the Federal University of Goiás, gathered from the people who were there.