The success of British wartime deception was also made possible by a degree of interdepartmental cooperation which was unimaginable in any of the other major combatants. The day-to-day selection of information and disinformation to feed to the enemy was entrusted to the imaginatively named Twenty Committee, so called because the Roman numeral for twenty (XX) is a double cross. The Committee, which had representatives from MI5, SIS, the War Office, the three service intelligence departments, GHQ Home Forces and, when necessary, other interested departments, began meeting in January 1941 and thereafter met weekly for the remainder of the war under the inspired leadership of its MI5 chairman, the Oxford history don J.C. Masterman (later knighted). Masterman preceded the first meeting of the Twenty Committee with what he later called 'a small but important decision, to wit that tea and a bun should always be provided for members':
'In days of acute shortage and of rationing the provision of buns was no easy task, yet by hook (and mostly by crook) we never failed to provide them throughout the war years. Was this simple expedience one of the reasons why attendance at the Committee was nearly always a hundred per cent?