of Britain the Observer Corps was granted the title Royal by King George VI and became a uniformed volunteer branch of the RAF from April 1941 for the remainder of its existence. Throughout its service the Royal Observer Corps was commanded by an RAF Air Commodore, each of whom served a tour of between three or four years. When the Corps' first Commandant Air Commodore Edward Masterman CB CBE AFC RAF(R’td) had stood down in April 1936, Air Commodore Alfred Warrington-Morris CB CMG OBE AFC MiD RAF(R’td) replaced him and took control of the Observer Corps in the important period immediately prior to the Second World War. He oversaw the move of HQ Observer Corps to Bentley Priory and the Corps' adoption by RAF Fighter Command. He also controlled the Corps during the memorable events of the Battle of Britain and was still at the helm when the Observer Corps was granted the title Royal to become the Royal Observer Corps and became a uniformed branch of the RAF. Warrington-Morris was Mentioned in dispatches in July 1940. The corps was created to provide a system for detecting, tracking and reporting aircraft over Britain. In World War II it was complementary to and often replaced the radar system in that it provided an 'over land' element while radar handled the 'over water approach' requirement. In 1955 the detection and reporting of nuclear blasts and fall-out was introduced. By 1965 the aircraft role was no longer needed and the corps formed the field force for the United Kingdom Warning and Monitoring Organisation (UKWMO) until both organisations were disbanded after the Cold war ended. Initially the Observer Corps' presence at Bentley Priory included not only the small headquarters' staff of a dozen officers and support staff but also around sixty spare time observers who filled essential plotting tasks in the Bentley Priory operations rooms. In 1955 the observers relocated to a new dedicated ROC operations centre in nearby Watford. By 1968 the ROC headquarters consisted of its Air Commodore, 9 full-time ROC officers and around 15 MoD civilian support staff. The ROC officers, several of whom 'lived in', took a full and active role in the life of the officers' mess and frequently filled mess committee positions. In 1992, a Royal Observer Corps stained glass window to mark the 50th anniversary of the Battle of Britain, was installed in the officers' mess at