Companys was a lawyer close to labour movement and one of the most prominent leaders of the Republican Left of Catalonia (ERC) political party, founded in 1931.

After the left-wing Popular Front won the Spanish national election in 1936, Companys was pardoned, and he returned to head the fractious Catalan government.

He obtained his law degree from the University of Barcelona, where he met Francesc Layret, another Catalan nationalist with an interest in politics.

With Francesc Layret, Companys represented the left-wing labour faction of the Partit Republicà Català (Catalan Republican Party), for which he was elected local councilor of Barcelona in 1916.

In November 1920, he was arrested together with Salvador Seguí (known as El Noi del Sucre), Martí Barrera and other trade unionists, and he was deported to the Castell de la Mola in Mahón, Menorca.

The law increased tensions, however, after it was contested by the Regionalist League, and it provoked a legal dispute with the Spanish government led by Ricardo Samper.

Meanwhile, the Generalitat established its own Court of Appeal (Tribunal de Cassació)[8] and assumed executive powers in public order, according as the Statute of Autonomy stipulated.

As a response to the 1936 Berlin Summer Olympics held in Nazi Germany, the government prepared the People's Olympiad in Barcelona, with Companys as its honorary president.

As a consequence of the independently organized resistance, by the end of the fighting on 21 July some of the political parties wielded considerably more power than the government.

[13] Companys was instrumental in organizing an umbrella collaboration between these diverse groups called the Central Committee of Anti-Fascist Militias (CCMA).

CCMA was formed on 21 July and sponsored by his Catalan government to reconcile the political tensions, recover the control of the situation, and organize the war effort.

Primarily objecting to Companys conciliation with anarchist groups, the conspirators intended to replace him with Prime Minister Joan Casanovas.

[14] Companys continued to try to maintain the unity of his fragile political coalition, but after the Soviet Union's consul, Vladimir Antonov-Ovseenko, threatened to cut off Russian aid to Catalonia for his continued collaboration with the anti-Stalinist POUM, he sacked POUM leader Andreu Nin from his post as Minister of Justice in December 1936.

After May Days, a series of clashes between Republican factions in early May 1937 which saw the removal of the central role played by the anarchist CNT-FAI, control of public order, defense, borders and war industries (in the hands of the Generalitat since the beginning of the war) was assumed by the Spanish Republican government.

As a consequence of Soviet/COMINTERN and Spanish Communist Party (PCE) pressures, POUM was declared illegal on 16 June 1937; Nin disappeared soon thereafter, widely viewed has having been assassinated by Soviet agents.

Ten days later he joined the half-million Republican soldiers and civilians in La Retirada escaping the Nationalists of Francisco Franco by crossing the Pyrenees of Catalonia to France.

Companys crossed the French border at Coll de Lli, La Vajol with the Basque lehendakari (president) José Antonio Aguirre on 5 February 1939, thus beginning his exile.

First detained in La Santé Prison in Paris, he was then extradited by Nazi German authorities to Spain in early September 1940.

During the trial, Companys was courageously defended by Ramón de Colubí, a young soldier who had fought in the war for the rebels.

[22] Lluís Companys is buried near the castle at the Montjuïc Cemetery within the memorial space Fossar de la Pedrera, which is dedicated to Republican victims of the Civil War.

[22][25] In recent years, multiple controversial and unsuccessful attempts have been made to rescind the guilty verdict of Companys' court martial.