From 1941 to 1979, Iran was ruled by King Mohammad Reza Pahlavi, the Shah. On February 11, 1979, the Islamic Revolution swept the country. The government was replaced with an Islamic republic, which continues to this day. For almost 40 years, Iran was ruled by the Shah, who led the country through a series of sweeping changes. The Shah pushed the country to adopt Western-oriented secular modernization in the decades before the Islamic revolution of 1979.