Ann Lambton, known as Nancy to her friends, devoted the greater part of her life to Iran and the study of Iran. Iranians who knew her thought she was either a saint, a scholar, a spy or all three. She was tough, physically and mentally, and almost an ascetic. She was a walker, a climber, a horsewoman and a squash player. She was a scholar who wrote some of the standard works on Iranian language, agriculture, land tenure and history. She was involved in some of the most dramatic of 20th-century Iranian political events. She was a devout Christian.

Lambton was the second child of the Hon George Lambton, fifth son of the 2nd Earl of Durham; and of Cecily, daughter of Sir John Horner. Her father trained racehorses, including George V’s, at Newmarket, and she was a good horsewoman herself. Her mother did not believe in education and kept her at home. She had almost no formal schooling and spent her youth in her father’s stables until she became too tall to be a jockey (a younger sister, Sybil, died in a riding accident in 1961).

At 16, Lambton later told a friend, she read T. E. Lawrence’s Revolt in the Desert and became fascinated by the idea of travel in Arabia. She later met Denison Ross, the orientalist and director of the School of Oriental Studies (later the School of Oriental and African Studies, SOAS, of London University), who encouraged her to study at the school. She enrolled in 1932 as a student not registered for a degree course. Ross persuaded her to concentrate on Persian rather than on the Arab world, and she later registered for an honours degree course in Persian with subsidiary Arabic.

Her first visit to Iran was in the summer vacation of 1934. She obtained her first degree in 1935 and, after winning an Aga Khan travelling fellowship, spent 1936-37 in Iran, and gained a PhD in 1939 with a thesis on Seljuk (pre-Ottoman Turkish) institutions. She spent much of her time in Iran in Isfahan where she made many close friends. She also worked at the British Hospital, run by Anglican missionaries, in Isfahan and got to know Persians whose families remained friends for the rest of her life. She also travelled widely, studying Iran’s economy and especially in agrarian questions while becoming expert in the language; her first book, Three Persian Dialects, was published in 1938.

Times Archive, 1941: Iran under Reza Shah

Security risked for national prestige by playing off Germany against the Allies

• Germans In Iran

• Oriental Studies

She was in Iran at the outbreak of the war and joined the British Legation (later Embassy) as press attaché. Her head of mission, Sir Reader Bullard, wrote in one of his letters home that her decision to go to Persia “was fortunate for us for she learnt Persian extremely well and made many Persian friends”.

Bullard also told the story that when he presented his credentials, the Shah had been interested to find a woman among the senior officials accompanying the ambassador, and even more so when he found that she spoke excellent Persian. There was no uniform for women, so she wore an academic gown and hood. Bullard noted that his press attaché “thus presented a striking appearance, not diminished by the fact that the hood was of the wrong colour, the wrong faculty and the wrong university”.

Lambton played an important role in the events leading up to the abdication of Reza Shah in 1941. His sympathy for Nazi Germany led to the Allied occupation of Iran in that year, and his replacement by his son, Muhammad (who was himself deposed in the 1979 revolution). Lambton first tried to see that the British news got its fair share of space as compared with news about Germany, and later did propaganda work, particularly supplying information to the Persian Service of the BBC about Reza Shah’s corruption and greed. She was seen ever afterwards by many Iranians as an éminence grise of the British Government, possibly even a member of the intelligence services. She was appointed OBE in 1943. In 1945 she returned to the UK and to SOAS, first as senior lecturer in Persian, later as reader and in 1953 as professor until her retirement in 1979.

It was as a scholar and teacher that Lambton most deserves to be known. Her knowledge of the language resulted in the publication, after Three Persian Dialects, of her Persian Grammar and then Vocabulary, used by many generations of students. She also published her minutely detailed analysis of land tenure in Landlord and Peasant in Persia which, it is said, supplied much of the detail on which the Shah’s land reform was based. Her investigations into land tenure took her everywhere in Iran, and she was known in the most remote villages.

Her later work, The Persian Reform 1962-66, also the result of tireless travel in the country, was critical of the way in which the land reform had been carried out.

She also wrote extensively on the politics, history, administration and religion of Iran, and her scholarship was fully recognised and honoured by the academic world; she became a DLitt of London University; a fellow of the British Academy; an honorary doctor of Durham and of Cambridge and of one of its colleges; and an honorary Fellow of SOAS.

Besides her university teaching, she taught Persian to many members of the Foreign Office in preparation for their postings to Iran or Afghanistan. Although her style of teaching was not considered by many as totally in keeping with modern theories, for most it provided the basis of a sound knowledge of the language, a lasting interest in Iran and an enormous admiration and affection for their teacher.

All who knew Lambton respected her not only for her intelligence but also for her physical strength and endurance. She was a fine squash player and often beat students a great deal younger than her. She always cycled between SOAS and her flat in Maida Vale. In Iran and in Northumberland she was a tireless walker up the steepest of hills at a huge pace and she walked everywhere in Iran, besides travelling on horseback or camel.