In the late 1930's, an aggressive and innovative rearmament program in Nazi Germany gave rise to the tactics of vertical envelopment. Luftwaffe General Kurt Student pioneered the use of gliders and airborne forces, and the Wehrmacht used them effectively early in the war as part of integrated, combined-arms offensives. Yet the German airborne branch literally self-destructed in May 1941 during the invasion of the island of Crete. This study examines the development of German airborne doctrine and addresses the questions of what happened on Crete, how the Germans reacted, and what historical insights modern day planners can derive from the German experience.