Condor Legion — Germany and Italy Enter the Spanish Civil War

After Franco's Nationalist uprising against Spain's Republican government, Nazi Germany and Fascist Italy intervened militarily, deploying the Condor Legion (German) and Corpo Truppe Volontarie (Italian). Germany used the conflict as a testing ground for new aircraft, tank tactics, and strategic bombing. The April 26, 1937 Condor Legion bombing of Guernica — a Basque civilian town — became the world's first deliberate mass aerial bombardment of civilians and inspired Picasso's famous painting.