The Battle of Crete (German: Luftlandeschlacht um Kreta; Greek: Μάχη της Κρήτης) was a battle during World War II on the Greek island of Crete. It began on the morning of 20 May 1941, when Nazi Germany launched an airborne invasion of Crete under the code-name Unternehmen Merkur ("Operation Mercury"). Greek and Allied forces, along with Cretan civilians, defended the island.
The Battle of Crete was unprecedented in three respects: it was the first mainly airborne invasion; the first time the Allies made significant use of intelligence from the deciphered German Enigma code; and the first time invading German troops encountered mass resistance from a civilian population. In light of the heavy casualties suffered by the paratroopers, Adolf Hitler forbade further large scale airborne operations. However, the Allies were impressed by the potential of paratroopers and started to build their own airborne divisions. This was the first battle where the Fallschirmjäger ("parachute rangers") were used on a massive scale