On this day, just 22 days after the end of the Battle of Crete, Hitler launched Operation Barbarossa, the German invasion of the Soviet Union. He had originally planned to begin the operation in the spring, but Italy’s failed campaign in Greece forced Germany to intervene. By the end of April 1941, and only after weeks of unexpectedly fierce resistance by Greek and Allied forces, mainland Greece was occupied by Germany, Italy, and Bulgaria. Crete, however, remained in Allied hands and had become a serious strategic thorn in Hitler’s side.

The determined resistance in both mainland Greece and Crete helped delay Barbarossa by precious weeks — a delay Hitler himself would later bitterly acknowledge in the rare Finland recording I share in my Battle of Crete stack: