This article sets out to explore the formation of the Central Treaty Organisation (CENTO), 1959-1979. It seeks to determine the aims with which CENTO was established, its failings, and the struggle that was undertaken against it by hostile countries. It examines the events surrounding its formation, development and collapse, and Anglo-American attempts to contain the Soviet Union in the Middle East. It also deals with British and American post-war defence policies in the Middle East and their collective defence projects in the region, such as the Middle East Command, the Northern Tier and Baghdad Pact, which led to CENTO. In addition, it looks at the policies of the local members and the organisation's internal structure. It poses questions of how the members of CENTO perceived the question of Middle East defence, what their basic aims were, and what problems they faced while trying to achieve these aims and implementing their chosen solutions. CENTO had its genesis in the Pact of Mutual Cooperation signed by Turkey and Iraq in Baghdad on 24 February 1955. Britain joined the Baghdad Pact on 5 April 1955, followed by Pakistan on 23 September and Iran on 3 November of the same year. While the United States strongly supported the creation of the Pact, for purely technical reasons of budgeting procedures, it never took up formal membership. On 14 July 1958, there was a military coup in Iraq, led by Brigadier Kassem, in which King Faisal, the Crown Prince, and the Prime Minister, Nuri Said, were all murdered. The new military regime did not immediately withdraw from membership, but it no longer participated in the work of the alliance. For the Baghdad Pact as a whole, the result was serious but not fatal. In October 1958, the Pact headquarters was moved from Baghdad to Ankara. On 24 March 1959, Kassem withdrew Iraq from the alliance and on 19 August 1959, it was announced in Ankara that the name had been changed from the 'Baghdad Pact' to the 'Central Treaty Organisation', abbreviated as CENTO. The membership remained unchanged: namely Turkey, Iran, Pakistan and Britain, with the US as a full participant. CENTO survived until 1979 when Iran withdrew from CENTO on 11 March following the Islamic revolution, claiming that 'it only protected interests of the imperialist states'. Pakistan followed suit on 12 March, because it believed that 'the organisation was not able to protect Pakistan's security'; and the next day Turkey proclaimed that 'CENTO had in effect lost its function in the region'. The history of CENTO has not so far been extensively researched and, as a result, the formation of CENTO and its overall aims are still surrounded by controversy. There are no comprehensive studies on the subject, though general information is given in a number of scholarly works. This article is based upon a range of primary and secondary sources. Much of material for this study was gathered from the National Archives, the United Kingdom.