Mohammed Reza Pahlavi (1919-1980), the Shah of Iran from 1941 to 1979, a period of tumultuous changes in the world oil market. With Iran's great oil wealth, Pahlavi became the preeminent leader of the Middle East. However, in 1979, the religious opposition, lead by Ayatollah Ruhollah Khomeini, drove Pahlavi into exile. Khomeini sought the capture of the Shah, and when it was learned that he had been admitted into the United States for medical treatment, Iran responded by initiating the hostage crisis at the U.S. embassy in Teheran, Iran. This event contributed to a sharp rise in oil prices, which ultimately triggered a global recession. Once the Shah's course of treatment had finished, the American government, eager to avoid further controversy, sent Pahlavi out of the country. Pahlavi was welcomed by President Anwar Sadat of Egypt, where he remained until his death in 1980.