The last occasion on which I addressed the Society, in 2000, was, like today's, a memorial lecture: to honour the memory of Professor Charles Beckingham. I spoke then about a subject that combined Professor Beckingham's interests with my own: Ibn Battuta and the Mongols. As it happens, I have already done something similar for Professor Lambton: a 90th birthday lecture to the British Institute of Persian Studies, in 2002, when my subject was a reappraisal of the Mongol period in Iran. This was given in the presence of the honorand: a slightly daunting experience; and those who knew her will not be surprised to learn that she was by no means uncritical, if not necessarily of what I said, then certainly of my delivery of it. So I decided that today I would talk about Professor Lambton herself, and attempt to discuss and evaluate her contribution to the field of study which she adorned for so long.