Between 1974 (the year of the ‘25 de Abril’ revolution in Portugal) and 1977 (date of the first general elections in Spain), the Iberian Peninsula experienced the end of two long dictatorships and the beginning of its democratic regimes. Although different in their formation and transition processes, the Portuguese and Spanish experiences have common aspects, one of which is the focus of this internacional congress: the emergence of social movements that contributed to deepening the system’s real democratization.