 It organized the mobilization of tens of thousands of mostly communist volunteers from around the world, who formed the International Brigades.In 1936, the Left united in the Popular Front and were elected to power.However, this coalition, dominated by the centre-left, was undermined both by the revolutionary groups such as the anarchist Confederación Nacional del Trabajo (CNT) and Federación Anarquista Ibérica (FAI) and by anti-democratic far-right groups such as the Falange and the Carlists.