On this day in 1957, the Ismaili sect of the Shi'ite Muslims welcomes a new spiritual leader when Prince Karim Al-hussain of Pakistan is proclaimed Aga Khan IV. Prince Karim’s grandfather, Aga Khan III, died the previous day after a 72 year reign. The title Aga Khan, which means chief commander, was first conferred on the leader of the Ismailis by the shah of Iran in 1818. Aga Khan I later rose up in revolt of the shah’s successor, but was defeated and fled to India. The second Aga Khan reigned for only four years before Aga Khan III, or Sultan Sir Mohammed Shah, came to power in 1885. Aga Khan III became an important leader to all of Indian’s Muslims, not just the Ismailis, and bypassed his own son to pick his grandson as heir. First criticised as a wealthy jet setter, Aga Khan IV devoted much of his time and money to the development of Ismaili communities in Pakistan and elsewhere.