1953 Iranian coup d'état
The 1953 Iranian coup d'état, known in Iran as the 28 Mordad coup, was the overthrow of the democratically elected Prime Minister Mohammad Mosaddegh in favour of strengthening the monarchical rule of Mohammad Reza Pahlavi on 19 August 1953, orchestrated by the United Kingdom (under the name "Operation Boot") and the United States (under the name TPAJAX Project).
Mossadegh had sought to audit the books of the Anglo-Iranian Oil Company (AIOC), a British corporation (now BP) and to change the terms of the company's access to Iranian petroleum reserves. Upon the refusal of the AIOC to co-operate with the Iranian government, the parliament (Majlis) voted to nationalize the assets of the company and expel their representatives from the country.
Following the coup in 1953, a government under General Fazlollah Zahedi was formed which allowed Mohammad-Rezā Shāh Pahlavi, the Shah of Iran (Persian for king), to rule the country more firmly as monarch. He relied heavily on US and UK support to hold on to power until his own overthrow in February 1979.
In August 2013, 60 years after the coup, the American Central Intelligence Agency (CIA) admitted that it was involved in both its planning and its execution, including the bribing of Iranian politicians, security and army high-ranking officials, as well as pro-coup propaganda.
https://en.wikipedia.org/wiki/1953_Iranian_coup_d'état