jan 1, 1936 - Spanish Civil War
Between 1936 and 1939, Germany and Italy lent support to the Nationalists led by general Francisco Franco in Spain, while the Soviet Union supported the existing democratically elected government, the Spanish Republic, led by Manuel Azaña. Both sides experimented with new weapons and tactics. The League of Nations was never involved, and the major powers of the League remained neutral and tried (with little success) to stop arms shipments into Spain. The Nationalists eventually defeated the Republicans in 1939.
Added to timeline:
Causes of WWII