The "Frente Occidental" refers to a political and military alliance formed during the Spanish Civil War (1936-1939). This coalition primarily consisted of leftist groups, including the Spanish Socialist Workers' Party and the Communist Party of Spain, who united against the Nationalist forces led by Francisco Franco. Their goal was to defend the Spanish Republic and promote social reforms. The Frente Occidental played a crucial role in various battles, particularly in the defense of key cities like Madrid and Barcelona. Despite their efforts, the alliance faced internal divisions and challenges, ultimately leading to the defeat of the Republican side and the establishment of Franco's dictatorship.