New Delhi, July 4 -- A hundred years ago, a modest office in Calcutta could influence the price of tea in London, finance a coal mine in Bengal, appoint the directors of a jute mill, insure a fleet of steamships and decide whether a new engineering unit should be built. That office belonged to Andrew Yule & Co., the managing agency that made David Yule, the man who ran it, arguably the most powerful businessman in British India.

The entry on the Yule family in the Oxford Dictionary of National Biography, a biographical record of people who shaped British history, describes David as "arguably the most important businessman in India." The Times of London, in its 1928 obituary, called him one of the wealthiest men in the country, if not the...