May 12, 1943. The Afrika Korps Surrenders.

 Axis forces in North Africa surrendered.

This was the first full theater collapse of an Axis army during World War Two.

Regarding this event, Sarah Sundin notes:

Today in World War II History—May 12, 1943: 80 Years Ago—May 12, 1943: German and Italian troops surrender in Tunisia, ending the campaign in North Africa; Allies take 225,000 prisoners.

The Axis surrender was affected by Colonel General Hans-Jürgen von Arnim and General Giovanni Messe, commanders, of the German Army and the Italian Army in North Africa.  Von Arnim refused to surrender the terms of the unconditional surrender, although his troops were surrounded and in fact were surrendered.

Messe.

Messe had experience in armored warfare, and had served on the Russian Front prior to being posted to North Africa.  This is all the more remarkable when you consider that Messe was an Italian Royalist and would go on to serve as Chief of Staff of the Italian Co-Belligerant Army after Italy switched sides in the war, making him a unique figure.  He was popular with the Italian people and went on to serve in the Italian Senate.

Messe wearing Iron Cross and inspecting Italian troops in Russia.

He may be the only figure to have fought with the Germans on two fronts, and then against them in his homeland, as well as perhaps being the only commander to have fought against the Soviets on Soviet territory to go on to fight in an army allied to them.

He died in 1968 at age 85.

The Trident conference between Winston Churchill and Franklin Roosevelt commenced in Washington, D.C.  It would run for sixteen days.

Sundin, in her blog, also notes that the Indian Army evacuated Maungdaw.

The massive Battle of West Hubei commenced in China between the Nationalist Chinese Army and the Imperial Japanese Army.  The Japanese offensive would fail, with each army loosing about 25,000 casualties.

The "Fido" acoustic homing torpedo came into action in the North Atlantic, being used by a Royal Air Force B-24 to damage the U-456.