Government of the Islamic Republic of Iran world. The Islamic Republic of Iran created shortly after the Islamic Revolution. The first major demonstrations with the intent to overthrow the Shah Mohammad Reza Pahlavi began in January 1978, with a new, Islam-based, theocratic Constitution being approved in December 1979, ending the monarchy. The Shah fled Iran in January 1979 after large strikes and demonstrations against him and his regime paralyzed the country. Ayatollah Khomeini would return in February of the same year after a long period of exile, greeted in the capital of Tehran by several million Iranians. The final collapse of the Pahlavi dynasty occurred shortly after
Iran 20th century BC, northwestern Iran was part of the Kura-Araxes culture, which stretched into the neighboring Caucasus and Anatolia. Since the earliest second millennium BC, Assyrians settled in swaths of western Iran and incorporated the region into their territories. By the second millennium BC, the ancient Iranian peoples arrived in what is now Iran from the Eurasian Steppe, rivaling the native settlers of the region. As the Iranians dispersed into the wider area of Greater Iran and beyond, the boundaries of modern-day Iran were dominated by Median, Persian, and Parthian tribes. From the late 10th to the late seventh century