I've had a couple of questions recently about 'Jumbo' Travis, Sir Edward Travis. He was Deputy Head of GC&CS from 1919-1942, then Deputy Director (Services) 1942-44, then Director GCHQ until he retired in 1952. Apart from three cryptanalysts (Alexander, Tiltman and Turing) he was the only person to have a room named after him in the Doughnut when GCHQ moved there in 2001. He was obviously a key figure, but he really isn't well known.
He passed for Paymaster in 1909 and might have had a normal Paymaster career, but found himself posted as Secretary's Clerk to Admiral Jellicoe, the Commander in Chief on 4 August 1914. By 1916 he had been loaned to the Admiralty by Jellicoe for the compilation of cryptosystems to be used by the Fleet, Jellicoe having being astounded at Travis's breaking the codes used by the C in C himself.
When GC&CS was formed in November 1919 Travis became its number two, responsible for GC&CS's over mission, cipher security. He had a public persona as the UK's representative at international naval communications conferences, and was also responsible for acquiring the UK's first Enigma machine (now in the possession of GCHQ). He was unsuccessful as the person responsible for cipher security: although only able to advise, and not mandate, standards for security to UK ministries, his advice was dire, and he must carry a significant share of responsibility for the fact that all of UK military systems (with one exception) were being read by the Germans by June 1940. (It's interesting that the one exception, Typex, an Enigma clone made more complex than Enigma), was designed by an RAF officer who refused to allow GC&CS any say in the design of his machine.
By 1938 Travis had been given responsibility for the Service sections of GC&CS - though I'm not aware that anybody has looked at how this came about. (Was 'C' - at that time 'Quex' Sinclair - already looking for a wartime alternative to Denniston, GC&CS's Head?) The first period of GC&CS's time at Bletchley Park is normally told in terms of Denniston's increasing inability to manage the rapid expansion of wartime Sigint and gradually losing control, but rarely in terms of Travis's being able to be seen by everyone as the man who could make Bletchley work.
A year after Denniston's dismissal from Bletchley Park with the diplomatic and commercial mission, Travis was able for the first time to enunciate (at least in part) a vision for Sigint in which he would create an organisation in which GC&CS/GCHQ would be in command of Sigint and the military would merely provide manpower and intelligence requirements. His mastery over the 'comitology' - bending the committee structure created to oversee Sigint to give him what he wanted - gave him complete control over Second World War Sigint in the UK. He not only achieved this, but also made himself (and GCHQ) independent of SIS, allowing 'C' to retain the title of Director-General Sigint without any control or responsibility for it. He also developed Denniston's vision of UKUSA and developed a system of Sigint sharing that neither 'C' or anybody else was able to stop (perhaps better, that neither 'C' or anybody else was able to understand).
After the war, Travis created the GCHQ which would be so successful during the Cold War. He redrew the boundary between cryptanalysis and traffic analysis and allowed Sigint to become the predominant supplier of intelligence on the Soviet bloc to defence Intelligence.
Ironically, he never understood communications security beyond the basic codebook level of the first part of the First World War, and, after having some responsibility for the dire state of British insecurity until Sir Edward Bridges began to knock heads together in 1942, was happy to see Comsec as, first of all semi-independent of GCHQ, and eventually as an agency completely (well, almost completely) independent of GCHQ.
Travis isn't well known because he falls between the stools on which the myth of Second World War British Sigint balances. He understood cryptanalysis but wasn't a cryppie. He was a manager in an organisation which thought it could do without management. He saw the big picture of 'ownership of Sigint' before anybody else, and manipulated the committee structure to enable him to 'bag' ownership for GCHQ. But mainly he had a vision for what a Sigint organisation - an intelligence organisation in which each discipline needed to produce intelligence from the interception antenna to the finished end product report - might look like, a global vision he had conceived while the people with whom he was meeting were simply fighting to place their towels on deckchairs.