Mir Osman Ali Khan

Mir Osman Ali Khan ascended the throne of Hyderabad, the largest state in British India, on 29 August 1911 at 25. His fortune came from the Golconda mines, the world's sole diamond source, and his private treasury held £100 million in bullion and £400 million in jewels. Across 37 years he built Osmania University, Osmania General Hospital, the State Bank of Hyderabad, dams to prevent flooding, and the oldest reservoir in what's now Telangana. After India's independence in 1947 he refused to accede, hoping to stay sovereign or join Pakistan, but the Telangana Rebellion and the rise of the Razakars militia broke his grip. The Indian Army invaded in 1948 and annexed Hyderabad. He served as ceremonial Rajpramukh until 1956, donated 14,000 acres to landless farmers, and leased the orthopedic hospital he'd built to the government for 99 years at one rupee a month.