Why did ayatollah khomeini lead an opposition movement in iran against reza shah pahlavi

Ayatollah Khomeini lead an opposition movement in Iran against Reza Shah Pahlavi to overthrow the authoritarianism type of government that the people disliked and create a new government. The people were fed up with the rule of Pahlavi and they wanted the change. Ayatollah Khomeini took advantage of this mood and returned to his country from exile.