Gremlin Castle 1943-44

from The History of Royal Air Force Bentley Priory snd Stanmore Park by John F Hamlin.  Published by the London Borough of Harrow ISBN 0 901034 43 6

Air Vice Marshal ‘Sandy’ Johnstone referred to above was only 27 when,  in May 1944, he was promoted acting group captain on the Allied Expeditionary Air Force operations staff at Bentley Priory, preparing for the D-Day invasion. After the landings he moved to Normandy with General Eisenhower’s headquarters.