New Delhi, Aug. 22 -- At an age when most people are content to settle into history, 93-year-old Dr. Prathap Chandra Reddy is still busy writing it. He sits atop a healthcare empire spanning more than 70 hospitals, with a market valuation of over $13 billion, a figure that firmly anchors Apollo among the five most valuable hospital operators on the planet.

Ask the good doctor, though, and he is likely to tell you his job is unfinished. That answer will not surprise anyone who has followed the fascinating trajectory of his life.

Trained as a cardiologist in Britain, Reddy built a thriving practice in the US, only to give it all up because his father asked him to come home. Filial duty supplied the emotion, but patriotism had much to do w...