The Spanish Civil War was a major military conflict between right-wing Nationalists and left-wing Republicans that erupted after a coup d’état was staged by rebel generals against the democratically elected Republican government. Following the ‘defense of Madrid’, during which Republicans held off a Nationalist siege on the Spanish capital, the conflict settled into a war of attrition, with Spain divided into two radically opposed territories. On the Nationalist side, an authoritarian dictatorship bolstered by the fascistic Carlist and Falange militias under General Francisco Franco (1892–1975) emerged, representing the interests of Spain’s conservative and Catholic élites. On the Republican side, defenders of the government of President Manuel Azaña (1880–1940) organized around radical anarchist and socialist trade unions (CNT, UGT, POUM) and volunteer militias.