The Nizari Ismaili sect of the Shiite 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.
According to tradition, Aga Khan IV and his predecessors are said to be direct descendants of Ali, the cousin and son-in-law of the Prophet Muhammad, and Ali's wife Fatimah, Muhammad's daughter. The supporters of Ali and his successors became known as the Shiites, who comprise the second largest branch of Islam. Upon the death of the sixth imam--or spiritual leader--of the Shiites in A.D. 765, the majority of Shiites supported the succession of his youngest son, Musa al-Kazim. Those who supported the eldest son, Ismail, broke away from the main body of Shiites and became known as the Ismailis.
In the late ninth century, the Qaramitah Ismailis, who claimed direct descent from Ismail, began to establish themselves on the Arabian peninsula and in present-day Iraq. In the 10th century, the Fatimid Ismailis came to power in Tunis and Egypt and built a broad missionary network across the Arab world. In 1094, another schism split the movement over the succession of the Fatimid caliph al-Mustansir. Those who upheld the claims of the older son Nizar became known as the Nizari Ismailis.
Beginning in the late 11th century, the Nizaris began to spread across Persia (Iran) and Syria, and followers of the sect inspired terror throughout the Muslim world for their violence and blind obedience to their spiritual leader. Europeans called them "Assassins" (Arabic for "hashish smoker") for their alleged practice of taking hashish before carrying out political or religious murders. The Nizaris remained in political power until they were displaced by the Mongols and the Mamluks in the 14th century.
The Nizari religion survived, however, and two rival lines competed for the title of imam. By the 19th century, the lesser line had died out. The imam of the surviving Nizari line, Hasan Ali Shah, was governor of the Persian province of Kerman in the early 19th century and was in high favor of the ruler of Persia, Fath Ali Shah. In 1818, the shah conferred on him the title Aga Khan, which means "chief commander." In 1838, Aga Khan I rose up in revolt of the shah's successor, Mohammad Shah, 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 India's Muslims, not just the Ismailis, and bypassed his own son to pick his grandson as heir. On July 12, 1957, 19-year-old Prince Karim was proclaimed Aga Khan IV.
First criticized as a wealthy jet setter, Aga Khan IV devoted much of his time and money to the development of Nizari Ismaili communities spread throughout Pakistan, India, Iran, Syria, and Africa. A strong leader, he ordered his millions of followers to leave countries in which they were persecuted and to become citizens of nations in which they were allowed to practice their religion freely. The Aga Khan is known for his business acumen and continues his grandfather's successful thoroughbred-breeding enterprise. He is also the founder and chairman of the Aga Khan Development Network, which works to further social and economic development around the world. In 2005, the Aga Khan received the Andrew Carnegie Medal for Philanthropy.