In April 1973, between the 4th and 8th, the III Congress of the Democratic Opposition took place in Aveiro. Destined to present lists linked to the legislative elections that took place in October of that year, it integrated different ideological and political currents, associated with a heated, participative and very productive debate. Oppositionists from different generations and tendencies collaborated in it, including military personnel who, a year later, would participate in the Carnation Revolution. Half a century later, this initiative by the Commemorative Commission for the 50th Anniversary of the 25th of April intends to remember, contextualize and interpret this moment that contributed to the deterioration of the regime.