A husn or stronghold in Wadi Bayhan

The Telegraph, March 12, 2014

Nigel Groom, who has died aged 89, was an Arabist, historian, author, soldier, spy-catcher and perfume connoisseur. These pursuits saw him fend off a tribal assassination attempt in Aden, uncover a KGB spy embedded in the RAF and explain the association between frankincense and Christ’s divinity.

As a young Political Officer for the Colonial Service, Groom arrived in the British Protectorate of Aden in 1948. He was responsible for the north-eastern area, based in Bayhan, a remote emirate bordering the central Arabian Desert, and accessible only by small RAF aircraft. Two years later he took over the northern area, based in Al Dhali’, regarded at the time as a difficult, ungoverned tribal part of the Protectorate, riven by unrest fuelled by the Imam of Yemen in pursuance of his claims over the whole country.

At Christmas in 1950 the British agent for the western area of the Protectorate, Basil Seager, and his wife arrived to spend the holiday in Al Dhali’, unaware that a plot was afoot to assassinate both Seager and Groom (and their escort of Arab soldiers) at a Christmas Day lunch in a nearby village. However, while out for a walk with armed guards on Christmas Eve, Seager and his wife by chance met the chief assassin, a religious fanatic high on khat, and his party on their way to their assignment. The assassin stabbed Seager with his dagger, causing serious injury, and in the subsequent gunfight several of the escort and several assailants were killed. Groom signalled to Aden for a doctor, who arrived after a five-hour night-time journey over rough tracks, and for a substantial force of Aden Protectorate Levies, to leave early on Christmas morning to help counter a planned tribal uprising.

Nigel Groom commenced his second career in the early Sixties, as an officer in MI5. Posted to D (later K) Branch in 1964, he was to spend his working life in counter-espionage work. In 1965 he was the case officer for an elaborate investigation which uncovered RAF Warrant Officer Douglas Britten as a KGB spy. The evidence unearthed included one-time code pads, short-wave radio schedules, RV instructions, sketch-maps for dead letter boxes and, in a detail worthy of Ian Fleming’s imagination, a document copier disguised as a cigarette case.

Groom combined the drama of his working life with a quiet, inquisitive fascination for all things Arabic, not least its various heady scents. He published three specialist studies in the field of perfume, in which he explained that “incense has had a continuous religious significance throughout the entire expanse of history”.

Nigel St John Groom was born on April 26 1924, and grew up in Devon, where his father, the Reverend RW Groom, was a country rector. Educated at Haileybury and Magdalene College, Cambridge, Nigel joined the Indian Army in 1943 and served with the 3 Gurkha Rifles and, in Burma, with 2 Karen Rifles. Joining the Colonial Service after the war, he was posted to the Western Aden Protectorate.

His first duty was to oversee an operation, using RAF Lincoln bombers flown from Britain for the mission, against a Bedouin desert tribe which had rebelled against the rule of the Sharif of Bayhan . Political influence over heavily-armed tribesmen — racked by blood-feuds — was limited to messages to their leaders sent by runners. There were no roads or vehicles and travel was on horseback or camel or on foot. The area was unmapped and virtually unexplored, and wherever Groom went he would take bearings with a pocket compass for a sketch map of the country. In his account of this period, Sheba Revealed (2002), he described the terrain as “perhaps the roughest land to administer anywhere in the British Empire”.

In 1952 Groom married Lorna Littlewood, the daughter of a British official in the Burma government who had died on the trek to India out of Burma after the wartime Japanese invasion. After their spell in Al Dhali’ the couple moved to the Aden Secretariat handling Protectorate affairs, where Groom worked latterly as Assistant Chief Secretary. In 1958 they left for Nairobi (“like being on leave all the time after Aden”) where he worked first in the Kenya Cabinet Office and later as Defence Secretary in the East Africa High Commission. His secretariat responsibilities included the Royal East African Navy, based in Mombasa, and the running of the East African Intelligence Committee. The job came to an end with the granting of independence to the East African territories.

Groom was recruited by MI5 in 1962. After the Britten case, he joined a small team examining allegations being sponsored by the counterintelligence officer and scientist Peter Wright, and later given publicity by the journalist Chapman Pincher, that Sir Roger Hollis, the service’s former Director-General, had been a Soviet mole. Groom’s investigations showed that, in every one of the leads put to him by the so-called Fluency Committee investigating Hollis, that the evidence was inconclusive.

Subsequently he was ordered to plan and supervise all K Branch surveillance operations against the “legal” Soviet Bloc intelligence community in London; this included the elaborate operations surrounding the defection of the Russian agent Oleg Lyalin and the expulsion, in 1971, of 107 KGB and GRU officers masquerading as Soviet diplomats. Thereafter he returned to investigating espionage leads and was to become head successively of two of the investigating sections. With a record length of continuous service in K Branch, he ended up as one of M15’s most senior and experienced counter-espionage officers, with an unrivalled knowledge of the sophisticated espionage techniques employed by the USSR. Many of the major spy cases of the time passed through his hands.

Nigel Groom never lost his keen interest in the Arab world and especially in its pre-Islamic history, on which he became a noted expert. This was kindled during his early days in Bayhan, where he supported the American archaeologist Wendell Phillips in excavation projects. In 1976 he compiled an archaeological map of south-western Arabia, which was published by the Royal Geographical Society. With A Dictionary of Arabic Topography and Placenames (1983) he provided English definitions of several thousand Arabic words of topographical significance. He contributed regularly to the Bulletin of the Society for Arabian Studies and other academic journals, one special interest being the interpretation of Ptolemy’s map of Arabia.

His time in Bayhan had also introduced him to the incense trade, a fascination for which infused his study Frankincense and Myrrh (1981). The volume explored the nature and location of incense trees, the harvesting and bartering of crops, and how trade routes opened up to Europe. The book attracted the interest of an Omani company preparing to launch a new perfume; Groom agreed to advise them on the historical background of the natural ingredients they wanted to use. This research led to a dictionary-style reference book, The Perfume Handbook (1992) — revised as The New Perfume Handbook (1997). He was later commissioned to write The Perfume Companion (1999), designed for a wider readership