Japanese Forces

Lord Sempill - a pioneer of Japan's carrier arm.

Imperial Government of Japan.

Captain William Forbes Sempill, Master of Sempill (later 19th Baron Sempill), shows a Gloster Sparrowhawk aircraft to Japanese naval hero, Admiral Togo Heihachiro, Japan, 1921. Great Britain was the original pioneer of shipboard military aviation, launching the world's first true aircraft carrier in 1918. Her WW1 ally, Japan - which had obliged the British (and served their own interest) by clearing out the German concession of Tsingtao - was very interested in obtaining access to this new technology, but was initially rebuffed. However, in 1920, the British Foreign Office appears to have discovered the then-novel concept of foreign arms sales. As a result, a "civilian" delegation of naval aviation technocrats was dispatched to Japan to assist the Japanese Navy in matters of naval aviation. This delegation was headed by the Master of Sempill, who had two outstanding qualifications for the job - he was a blue-blooded Scottish aristocrat, and a leading WW1 flying ace with the Royal Flying Corps and (from 1916) the Royal Navy Fleet Air Arm. This cosy arrangement ended abruptly in 1922, when Britain's adherence to the Washington Treaty necessitated its termination of technical co-operation arrangements such as Sempill's mission. There, matters should have ended. End it did not. Sempill's two years in Japan had impressed him greatly; he developed a deep appreciation of Japanese culture, and a great respect for the military values of the new Japanese Navy and its officers with whom he had spent so much time. Added to what was to emerge as an extreme right-wing bent in politics (which was to lead to him to support the Nazis in time), a reckless nature and (it would appear) the fact that his income fell short of his preferred level of expenditure, Sempill's new-found affinity for things Japanese made him a huge security risk that was initially not perceived (surely the heir to a barony would behave like a Chap ?). Well, not quite like a Chap. By the time he returned to Britain from Japan, the Master of Sempill had clearly decided that, Washington Treaty or no, he would continue to share useful (and often secret) information coming his way with his Japanese friends. Sempill made contact with Captain Toyoda, Naval Attaché at the Japanese Embassy to the Court of St James. Operating as a sort of semi-official international arms trader, still connected to the British Government, he continued to have access to a great deal of information of a confidential and secret nature; also, he was well aware of what was classified as "secret", and what was not. Nonetheless, by letter, telephone and personal meeting, he passed a great deal of classified information to Toyoda, often on the latter's request, into the late-1920s. Among the areas in which the Japanese gained greatly from this contact was the technology of constructing the decks of aircraft carriers; developments in maritime aviation weaponry (notable torpedoes) and the particular characteristics required of carrier aircraft engines. All of these areas were classified "top secret". So - the British Security Service (MI5) was asleep on the job when it came to Sempill ? Er ... no. While he may not have been identified as a security risk initially, Sempill's suspicious behaviour (and he was not the most discreet of men) soon drew the attention of the counter-spooks. Starting with "invisible" mail intercepts, soon supplemented by clandesdine telephone taps, MI5 soon found itself in possession of a substantial, increasing, and irrefutable body of evidence that Sempill was communicating secret information to the Japanese in prejudice of his country's interests. How to deal with him ? Difficult, it turned out. If Sempill was a "common Joe", he could perhaps have been quietly "vanished". However, he was a highly-connected Scottish aristocrat; he could not simply be quietly sidelined or eliminated. Nor were MI5 enthusiastic about putting the prospective peer of the Realm on trial for his multiple manifest breaches of the Official Secrets Act. Even if the trial could be held in secret (not easy in the British system), it would undoubtedly unmask the then-top secret techniques of mail and telephonic interception used by MI5, and this was considered a price too high to pay. For a time, the British Government was at a loss to know what to do about Sempill who, to coin a phrase, carried on spying. On a trip to Brighton to view the new (and top secret) Blackburn Iris flying boat, he incautiously discussed the project with the Chilean Naval Attaché, whose Embassy reported the matter to the Foreign Office. MI5 had proof that Toyoda had communicated to Sempill a request for information on this project - which, of course, could not be used against Sempill without revealing MI5's surveillance. However, at about the same time, Sempill seems to have become aware that he was under some sort of surveillance, and requested a meeting with "the Ministry" to "clear the air". At that meeting, which was attended by the Director of Public Prosecutions, the "official side" were able to use Sempill's open discussion of the Blackburn Iris project (along with a lot of general questions about his relations with the Japanese) to "warn him off" future disloyal activities in that direction. This was, however, not the end of the matter. JR.