It's been 40 years since Iran's Islamic Revolution. Here's how the country has changed

TEHRAN, Iran - It's been 40 years since Iranians came together to topple the shah.

Stirrings of opposition became apparent in 1975. The shah, Mohammed Reza Pahlavi, who had been reinstalled in 1953 after the CIA helped overthrow democratically elected Prime Minister Mohammad Mossadegh, used tough and sometimes brutal measures to clamp down on dissent.

He replaced Iran's two-party political system with a single political organization, downplayed the role of Islam in public life and used his internal security organization, SAVAK, to jail and sometimes torture opponents.

Street protests finally began in September 1978, when Iranians from all walks of life clashed with armed forces in Tehran,