First Indochina War
Dien Bien Phu, Vietnam
Operation Castor was launched on November 20, 1953, with 1,800 men of the French 1st and 2nd Airborne Battalions dropping into the valley of Điện Biên Phủ and sweeping aside the local Việt Minh garrison. The paratroopers gained control of a heart-shaped valley 12 miles (19 km) long and 8 miles (13 km) wide surrounded by heavily wooded hills. Encountering little opposition, the French and Tai units operating from Lai Châu to the north patrolled the hills.