The 1953 overthrow of Iran’s nationalist prime minister, Mohammad Mossadegh, was largely orchestrated by American and British intelligence agencies. It saw power shift from a democratically-elected government to the US-backed Shah, Mohammad Reza Pahlavi, whose reign continued until 1979 when fundamentalist cleric Ayatollah Khomeini returned from exile to be religious and political leader of the world’s first Islamic republic. This timeline shows how the 1979 revolution has shaped Iranian-US relations.