The Ayatollah predecessor is SHAH, which is a four-letter word. The term 'SHAH' is an Iranian title given to the monarchs of Iran from 1501 to 1979. It was also used by some other countries in the Middle East and Central Asia. The SHAH was the head of state and held absolute power over the government and military. The last SHAH of Iran was Mohammad Reza Pahlavi, who was overthrown in the Iranian Revolution of 1979.