In 1941, 'A' Force (the Cairo-based department responsible for deception operations in the North Africa) had begun an operation, codenamed Cascade, to inflate the number of troops in the region by creating fictional divisions. By 1943 the use of notional formations had proved a useful part of deception operations, such as Operation Rayon, and the practice formed the basis for key parts of Bodyguard. The Allies invaded Italy in September 1943 and by the end of the year had occupied most of the south of the country. Thirty-eight divisions were deployed across the Mediterranean theatre, mostly in Italy with some in North Africa.