The Carlists supported the claim of the descendants of Don Carlos (the uncle of Queen Isabella II) to the throne of Spain. They wanted a return to a "traditionalist" ultra-Catholic monarchy. Although they hated the Alfonsine Monarchists, whom they regarded as too "liberal", they loathed the anti-clerical Republicans. The movement's support came from the Requetes (the Carlist Militia), the Pelayos (the Carlist Youth Movement) and the Margaritas (the Carlist Womans' Service), whose recruits were mainly drawn from the families of Navarrese smallholders.
The CEDA (Confederacion Espanola de Derechas Autonomas) was a composite right-wing Catholic party founded in 1933 by Gil Robles. It was formed from the Accion Popular and Partido Agrario, and had a youth movement known as the JAP (Juventudes de Accion Popular). Although successful in the 1933 elections, the Party virtually collapsed after the Popular Front victory in 1936. The membership of JAP then switched en masse to the Falange.
The Falange was a small fascist party that was founded in 1933 by Jose Antonio Primo de Rivera. It gained a degree of popular support when it merged with the JONS (Juntas de Ofensiva Nacional-Sindicalista), in 1934, to form the Falange Espanola de las JONS.
The Monarchist groups, which included Accion Espanola and Renovacion Espanola, supported the claim of the descendants of Queen Isabella II to the throne of Spain. The Monarchist movement, which had the support of conservative army officers, became the focus of opposition to the Republic after the abdication of King Alfonso XIII.
The Anarchist movement in Spain was the strongest in Europe. Its main support came from the industrial workers of Barcelona, who formed the anarcho-syndicalist trades union, the CNT (Confederacion Nacional de Trabajo), in 1911. The Anarchist also founded a youth movement, the FIJL (Federacion Iberica Juventudes Libertarias), to promote anarcho-syndicalist beliefs amongst the young. The most influential organisation within the Anarchist movement was the FAI (Federacion Anarquista Iberica); this was a federation of militant anarchist groups founded in 1927. It worked in secret, and formed the backbone of the Anarchist Militias at the outbreak of the Civil War.
The Basques had always considered themselves to be a separate nation. The region had its own language, culture, traditional laws and style of government, and its people looked to the Republic to reintroduce the autonomy that had previously existed. The PNV (Partido Nacionalista Vasco), the main Basque Nationalist Party, was founded in 1895 and enjoyed popular support in the Basque region.
Like the Basques the Catalans thought of themselves as separate from Spain. They too had a language and culture of their own, and expected to gain autonomy when the Republic was founded. The main Catalan political parties were the ERC (Esquerra Republicana de Catalunya), which was a Left Republican nationalist party founded in 1931, and the PSUC (Partido Socialista Unificado de Cataluna), the United Catalan Socialist Party, which was formed in 1936 from several Socialist and Communist groups. The latter was affiliated to COMINTERN and was the Communist Party in Catalonia.
The PCE (Partido Comunista de Espana) was founded in 1921. Due to the strength of the Socialist, Anarcho-Syndicalist and Marxist movements in Spain, the Spanish Communist Party was small; it was also highly efficient and enjoyed the support of Stalinist Russia. This was to prove highly significant as the Civil War progressed; as the other political parties declined in power the Communists were to exert more and more influence, especially in the Armed Forces.
The revolutionary anti-Stalinist Marxist Party, the POUM (Partido Obrero de Unificacion Marxista), was formed in 1935 as the result of the merger of the BOC (Workers and Peasants Bloc), led by Joaquin Maurin, and Izquierda Comunista (Left Communist Party), led by Andres Nin.
The two main republican parties were founded in 1934. They were the Izquierda Republicana (Left Republican Party), which was formed from four smaller left-wing social-democratic groups, and the Union Republicana (Republican Union Party), which had broken away from the Partido Republicano Radical (Radical Party).
The Socialists were the most powerful left-wing political force in Spain before the Civil War. The Spanish Socialist Workers Party, the PSOE (Partido Socialista Obrero Espanol), was founded in 1879; it was supported by the Socialist Trades Union, the UGT (Union General de Trabajadores), and the Socialist Youth Movement, the FJS (Federacion de Juventudes Socialistas). The latter amalgamated, in 1936, with the Communist Youth Movement to form the Unified Socialist Youth or JSU (Juventudes Socialistas Unificadas); this was soon dominated by the Communists.