The Spanish Civil War, erupting in July 1936, was a ferocious conflict that claimed over half a million lives and reshaped Spain for decades. For nearly three years, the leftist Second Republic battled a right-wing Nationalist uprising led by General Francisco Franco. More than a domestic struggle, it became a global crucible of ideologies—democracy versus fascism, socialism versus authoritarianism—drawing intervention from Nazi Germany, Fascist Italy, and the Soviet Union.