On 14 December 1940 Berryman and Mackay arrived at Lieutenant-General Richard O'Connor's Western Desert Force headquarters. This was the start of an exceptionally close and smooth working relationship that developed between 6th Division headquarters and Western Desert Force (XIII Corps) during the campaign. Berryman was one of the foundations of this relationship, which was built on the connections he had forged before the war with a number of the senior British officers. O'Connor had been one of Berryman's instructors at Camberley, and his chief of staff, Brigadier Harding, had been a fellow student at Staff College with Berryman, as had the corps principal supply and administration officer, Colonel Navis. Berryman noted after the war: ‘When with 6 Div in the Middle East, I knew most of the key officers in the British forces, while Vasey knew them in the Indian Division, so through personal contact the doors of cooperation opened easily – and General Mackay, our GOC, more than once said how greatly impressed he was by this advantage of staff college graduates knowing each other and by its value to the army.’ To Berryman this type of relationship was proof that ‘the graduates of the Staff Colleges, Camberley and Quetta, are the cement that binds the parts of the Army into a homogenous whole, they are the axle on which the machine functions and many other things besides.’ The ‘Army’ to which Berryman referred was one that was a truly imperial entity.