New Delhi, July 5 -- Long before the first unicorns and decacorns appeared in India, there lived an entrepreneur who had an innate understanding of scale and an uncanny ability to leverage diaspora networks.

Had Annamalai Chettiar (Satappa Ramanatha Muthiah Annamalai Chettiar) been alive, he would have been called upon to deliver TED talks on banking without borders. Instead, this pioneering businessman from Tamil Nadu, who wrote the playbook for colonial banking in India, remains largely forgotten outside academic circles, though the posh Raja Annamalai Puram neighbourhood in Chennai is named in his honour.

At a time when Indian companies are going global with unabashed ambition, his century-old blueprint for international expansion re...