On 9 January 1915, M. K. Gandhi disembarked in Bombay to a hero’s welcome. His ideas and personal leadership exercised a powerful pull on India’s nationalist elite, and were seen by many to hold the political key to the country’s future. For a young Calcutta student of the time: “[a]lready . . . the man who was to bring in the masses and conduct the passive resistance campaign had become identified to us as Mr. (not yet Mahatma) Gandhi. Although all the old leaders . . . were still living and active, our eyes were fixed on Gandhi as the coming man”.

Yet Gandhi had spent little of his adult life in India. He had been a student in England, and had subsequently made several extended visits there; and for more than two decades, his home had been in southern Africa. How, then, was Gandhi able to achieve a position as a major Indian public figure from outside the country? This was all the more remarkable because, in his early years, he had shown little trace of personal or intellectual distinction. The Gandhi who went to the colony of Natal in 1893 had not been an outstanding student and had failed in his attempt to make a legal career in India because of his intense shyness. So another puzzle arises: what sort of personal transformation could have underpinned his rise?