On 16 and 17 October 1973, during the Yom Kippur War, the Arab countries in the Organisation of Petroleum Exporting Countries (OPEC) meet in Kuwait and announce an embargo on oil supplies to states that support Israel. The oil crisis results in a fourfold increase in the price of a barrel of oil for five months, from 17 October 1973 to 18 March 1974, and has a severe impact on Western economies. On 18 March 1974, following the OPEC conference in Vienna and after months of standoff, the oil producing countries decide to lift the embargo on oil supplies. This photo, taken on 16 March 1974, shows the Arab delegation at the OPEC conference in Vienna. In the centre, smiling, is Sheikh Ahmed Zaki Yamani, Saudi Arabian Minister for Oil.