The International Brigades were volunteer military units formed during the Spanish Civil War (1936-1939) to support the Republican side against the Nationalists, led by Francisco Franco. These brigades consisted of individuals from various countries, including the United States, France, and Germany, who were motivated by anti-fascist sentiments and a desire to defend democracy. The brigades played a significant role in several key battles, providing crucial support to the Republican forces. Despite their efforts, the Republicans ultimately lost the war, leading to Franco's dictatorship, which lasted until his death in 1975. The legacy of the International Brigades remains a symbol of international solidarity against fascism.