[6] After the fall of Primo de Rivera (1930), the Catalan left made great efforts to create a united front under the leadership of left-wing independentist leader Francesc Macià.

[8] In September 1932, the Spanish Republican Cortes approved the Statute of Autonomy of Catalonia which, among other provisions, granted a Catalan Parliament with full legislative powers, and it was elected on 20 November 1932.

CEDA was considered close to fascism and, therefore, it was feared that this was the first step towards suppressings the autonomy and taking complete power in Spain.

[11] The party leaders (including Companys itself) and the Catalan government were sentenced by the Supreme Court of the Republic and jailed, while the Statute of Autonomy was suspended until February 1936.

During the Spanish Civil War ERC, as the leading force of the Generalitat, tried to maintain the unity of the Front in the face of growing tensions between the Workers' Party of Marxist Unification (POUM) and the pro-soviet Unified Socialist Party of Catalonia (PSUC), while struggled to recover the control of the situation, de facto controlled by the anarchist trade union CNT and their militias, and attempted to organize the war efforts in Catalonia.

President Companys appointed Josep Tarradellas Conseller Primer (Prime Minister) in order to form a coalition government with the other Republican forces, including anarchists and communists.

However, the party unsuccessfully tried to avoid the full control of Catalonia by the Republican government, enacted after the May Days event.

The former president of the Catalan Generalitat, Lluís Companys, was arrested by Nazi German agents[13] in collaboration with Vichy France, returned to Spain and executed on 15 October 1940 in Montjuïc Castle, Barcelona.

[14] Since 1939, despite the weak situation of the party, almost disbanded after the Francoist occupation of Catalonia, ERC went underground and tried to organize anti-fascist resistance around Manuel Juliachs and Jaume Serra.

At the end of World War II, in view of a possible overthrow of Francoist Dictatorship with the intervention of the Allied forces, the direction of ERC in exile sent to Catalonia Pere Puig and Joan Rodríguez-Papasseit.

On 11 September 1964, the National Day of Catalonia, ERC and other groups organized the first anti-Franco demonstration since the end of the war.

[16] In 1984, however, ERC only obtained five deputies, and began a brief period of decline, overshadowed by the hegemony of the center-right Catalan nationalist coalition CiU.

In 1987, the National Call manifesto was published, signed by personalities like Àngel Colom and Josep-Lluís Carod-Rovira, who wanted ERC to bring together the new generation of independentists that aroses as a result of the disenchantment with the Spanish Transition.

The 18th National Congress of ERC, held in June 1992, approved the reform of its statutes in the face of electoral growth, militancy and territorial presence.

ERC advocates in its first statutory article the territorial unity and independence of the Catalan Countries, building its own state within the European framework and together with an ideological position of the left that takes the defense of democracy and environment, human rights and rights of the peoples, and based its ideology and political action on social progress and solidarity.

ERC recovered the presence in many local councils of Catalonia, reaching more than 550 elected councillors and 32 mayors, and thus becomes the third municipal political force.

The militants chose a new direction for the party, with Josep Lluís Carod-Rovira as new president and Joan Puigcercós as new general secretary.

The other five ministries assumed by ERC were Education (Josep Bargalló), Welfare and Family (Anna Simó), Commerce, Tourism and Consumption (Pere Esteve), Government and Public Administration (Joan Carretero) and Universities, Research and Information Society (Carles Solà).

This is organised into the three areas that give the organisation its name: Esquerra (commitment to the Left's agenda in the political, economic and social debate), República (commitment to the Republican form of government vs. Spain's current constitutional monarchy) and Catalunya (Catalan independentism, which, as understood by ERC, comprises the Catalan Countries).