Cartas à Guiné-Bissau, published in 1977 in Rio de Janeiro and the following year in Lisbon, is a collection of correspondence sent by the Brazilian educator Paulo Freire to Mário Cabral, Minister of Education of Guinea-Bissau from 1974 and former coordinator of training centres during the war of liberation. The book goes back to the work carried out by the Institute for Cultural Action (IDAC), founded in Geneva four years earlier by Paulo Freire and other Brazilian compatriots in exile. Freire also presented his conception of the political role of teachers at each stage of the educational pathway built collectively in Guinea-Bissau. A contemporary of Freire, the French anthropologist Roland Colin, took over the International Institute for Research and Training in Education and Development (IRFED) following the death of Father Louis-Joseph Lebret in 1966. A former student of Léopold Sédar Senghor at the École nationale de la France d’Outremer, Colin was until 1962 cabinet director and then personal adviser to Mamadou Dia, head of the Senegalese government. At the same time as Freire in Guinea-Bissau, he supervised the construction and operation of Integrated Popular Education Centres (CEPI) in rural areas, also under the leadership of Mário Cabral. We wish to examine the role of these two individual international figures to take the measure of their action, while also learning to decentralise the historical perspective. Their projects in favour of popular education and adults literacy in Guinea-Bissau, which began in 1974, are situated at the heart of complex militant networks, made up of a diversity of actors, personal connections, life trajectories, material contingencies and multiple commitments. We will analyse those circumstances by placing them in a historiographic moment at the crossroads of different temporalities: the period of Brazilian exile coincides with the rise of Third Worldism, the Liberation theology and, of course, the struggles for independence of the PALOPs. In sum, it’s about presenting the contours of the transnational trajectories that turned them into educational activists and builders, among others from the sources they produced.