Spanish Civil War: The German Condor Legion, equipped with Heinkel He 51 biplanes, arrives in Spain to assist Francisco Franco's forces.

The Spanish Civil War was fought from 1936 to 1939 between the Republicans and the Nationalist rebels. Republicans were loyal to the left-leaning Popular Front government of the Second Spanish Republic and included socialists, anarchists, communists, and separatists, supported by the Soviet Union. The opposing Nationalists were an alliance of fascist Falangists, monarchists, conservatives, and traditionalists, supported by Nazi Germany and Fascist Italy and initially led by a military junta, until General Francisco Franco was appointed supreme leader on 1 October 1936 for what he called the Spanish State. Due to the international political climate at the time, the war was variously viewed as class struggle, religious struggle, or struggle between republican democracy and dictatorship, revolution and counterrevolution, or fascism and communism. The Nationalists won the war in early 1939, and ruled Spain until Franco's death in November 1975.