In April 1951, the Iranian government nationalised the Iranian oil industry by unanimous vote, and the National Iranian Oil Company (NIOC) was formed, displacing the AIOC.The AIOC withdrew its management from Iran, and Britain organized an effective worldwide embargo of Iranian oil. The British government, which owned the AIOC, contested the nationalisation at the International Court of Justice at The Hague, but its complaint was dismissed.
1951 Price's developed the first multigrade oil, Energol, at its Battersea works.
1951 Iran’s prime minister convinced his Parliament to nationalize oil operations within the country’s borders. Women and children were evacuated and the refinery was shut.
Governments around the world boycotted Iranian oil. Within 18 months, the Iranian economy was in ruins. Eventually a new arrangement was made, allowing a consortium of companies, including Standard Oil of Indiana (Amoco) and others, to run the oil operations in Iran. Anglo-Iranian’s stake was 40%.
Prime Minister Churchill asked President Eisenhower for help in overthrowing Mossadeq. The anti-Mossadeq plan was orchestrated under the code-name 'Operation Ajax' by CIA, and 'Operation Boot' by SIS(MI6). The CIA and the British helped stage a coup in August 1953, the 1953 Iranian coup d'état, which established pro-Western general Fazlollah Zahedi as the new PM, and greatly strengthened the political power of Shah Mohammad Reza Pahlavi. The AIOC was able to return to Iran.
In 1953 British Petroleum entered the Canadian market through the purchase of a minority stake in Calgary-based Triad Oil Company, and expanded further to Alaska in 1959, resulting discovery of oil at Prudhoe Bay in 1969. In 1956, its subsidiary D'Arcy Exploration Co. (Africa) Ltd. has been granted four oil concessions in Libya
1953 Opened Kent refinery on the Isle of Grain and another refinery in Belfast.
1954, the board changed the company’s name to the British Petroleum Company.
1954 Increasing demand for multigrade oil led BP, part owners of Price's, to remove the lubricating oil business to the refinery at Grangemouth and re-brand it as their own product.
In 1954, the AIOC became the British Petroleum Company. After the 1953 Iranian coup d'état, Iranian Oil Participants Ltd (IOP), a holding company, was founded in October 1954 in London to bring Iranian oil back to the international market. British Petroleum was a founding member of this company with 40% stake. IOP operated and managed oil facilities in Iran on behalf of NIOC. Similar to the Saudi-Aramco "50/50" agreement of 1950, the consortium agreed to share profits on a 50–50 basis with Iran, "but not to open its books to Iranian auditors or to allow Iranians onto its board of directors."
1955 Introduction of Visco-Static multigrade lubricating oil.
1957 BP welcomed the purchase of National Benzole Co by Shell-Mex and B. P. which would consolidate the long standing arrangement for supplying product to National Benzole.