Ann Katherine Swynford Lambton (often known as Nancy) was the foremost British scholar in the field of Persian studies in the second half of the twentieth century; her towering status can rightly be compared only with that of E. G. Browne in the preceding generation. She was born on 8 February 1912 and died on 19 July 2008, aged ninety-six.

Her background and upbringing within the British aristocracy were highly unusual for the career on which she subsequently embarked and to which she would devote her working life. On her father's side she stemmed from a landed family in Northumberland. She was a daughter of the Hon. George Lambton, son of the second Earl of Durham (the first Earl having achieved fame in the 1830s as author of the Durham Report on the governance of the Canadian provinces). Her mother came from the ancient Somerset family of the Horners of Mells. Her father was a famous rider and breeder of horses at Newmarket, and her own Christian name of ‘Swynford’, with its medieval resonance, came from her father's famed St Leger winner of that name, the colt's sire being called ‘John o’ Gaunt’. Brought up at home, she had no formal schooling, but she did become an excellent horsewoman, and these riding skills were to stand her in good stead when travelling around the Iranian countryside on horse, donkey and camel. She was also a keen squash player (she was said to have regularly won matches against several of her male students until quite late in life), and back in Britain from Iran after the Second World War, she became an intrepid cyclist around London and in rural Northumberland.

Having read T. E. Lawrence's Revolt in the Desert, the lure of the East cast its spell over her, and a family friend, Sir E. Denison Ross, the first Director of the School of Oriental Studies (as it then was), encouraged her to enroll at the School in 1930, in the first place as a non-degree registered student and then in 1932 to follow a degree course.