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
Supreme Headquarters Allied Expeditionary Force to this day. Southwick House was used as an alternative headquarters near Portsmouth. Its staff took the outline plan for Operation Overlord created by Lieutenant General Sir Frederick E. Morgan, Chief of Staff to the Supreme Allied Commander (Designate) (COSSAC), and Major General Ray Barker. Morgan, who had been appointed chief of staff to the Supreme Allied Commander (designate) in mid-March 1943 began planning for the invasion of Europe before Eisenhower's appointment. and moulded the plan into the final version, which was executed on 6 June 1944. That process was shaped by Eisenhower and the land forces commander for the