Sheikh Yamani became a household figure across the Western world in the 1970s, as the very public face of the newly empowered Gulf Opec states.

A long-serving Saudi oil minister – in power from 1962 to 1986 – he played the pivotal role in the 1973 oil embargo that swung market power away from the largest Western oil companies to the Opec states; it was he who devised the scheme to quadruple oil prices.

A commoner among princes, this smooth-talking technocrat was at ease dealing with oil company CEOs and foreign heads of state. He, more than anyone else, smoothed the kingdom’s path to becoming the world’s central bank of oil.