Supreme Headquarters Allied Powers Europe government offered Camp Casteau, a 2 km² Belgian Army summer training camp near Mons, which was an area in serious need of additional economic investment. In September 1966, NATO agreed that Belgium should host SHAPE at Casteau. SHAPE closed its facility at Rocquencourt near Paris on 30 March 1967, and the next day held a ceremony to mark the opening of the new headquarters at Casteau. The drawdown of the British Mediterranean Fleet, the military difficulties of the politically decided command structure, and the withdrawal of the French from the military command structure forced a rearrangement of the command arrangements
NORTHAG wartime structure in 1989 There were two additional French corps (III Corps, ) associated with the Army Group. In 1966, France had withdrawn from the NATO Command Structure, but still wished to take part in the defence of Western Europe. A series of secret agreements made between NATOs Supreme Allied Commander Europe (SACEUR) and the French Chief of the Defence Staff detailed how French forces would reintegrate into the NATO Command Structure in case of war. At the outbreak of hostilities the French First Army would be placed directly under the command of Supreme Headquarters Allied Powers Europe (SHAPE), which would employ the three