For 81 years three generations of Oppenheimers have built a business set up with pounds 1m into a unique company - a pounds 6bn conglomerate whose interests range from gold, platinum, diamonds, coal and copper into manufacturing, banking and financial services, in South Africa and abroad.
The company has grown into a complex network of inter-dependent companies, reinforced by crossholdings of shares and interlocking directorships.
The Oppenheimers kept open links with the world outside apartheid South Africa. At home they established an impressive network of contacts in politics and finance, employing Rhodes scholars and acting as a pillar of the English-speaking business community. They co-operated with the post-1948 Nationalist governments, yet maintained a reputation as the conscience of liberal capitalism.
Sir Ernest built the company mainly on gold mining. In the 1920s he moved back into diamonds and set up a rival to the Diamond Syndicate and the leading producer, De Beers. By 1929 he had become chairman of De Beers and established the Diamond Corporation, which had a global monopoly in the marketing of diamonds.
In 1928 Anglo American acted as consulting engineers to a group of companies developing the copper mines of Northern Rhodesia, then absorbed them into a new company, Rhodesian Anglo American, which became Mineral and Resources Corporation, and finally Minorco.
The gold, diamond and copper mines were reorganised into holding companies with their own access to outside capital, as Anglo diversified into manufacturing, brewing, banking and financial services.
The Nationalist government elected in 1948 encouraged the establishment of rival companies controlled by Afrikaners. But Harry Oppenheimer, Sir Ernest's son who succeeded as chairman in 1957, kept Anglo's relations with the government sweet while maintaining links with the outside world.
In 1965 Anglo merged its mining interests to form Charter Consolidated, which gave it investment opportunities outside South Africa. In 1971 the newly independent government of Zambia nationalised the country's copper mines, but Anglo American used the $75m it received in compensation to create Minerals and Resources Corporation as a mining investment trust.
As South Africa became isolated Anglo grew nervous about its position and the Oppenheimers began to criticise apartheid. In 1985 Gavin Relly, who succeeded Harry Oppenheimer as chairman in 1982, met representatives of the ANC.
In 1987 the Minerals and Resources Corporation was renamed Minorco, moving to Luxembourg. Minorco was given control of all Anglo's assets outside Africa in return for a 45.6 per cent shareholding.
After majority rule in South Africa, the dual structure is superfluous and Anglo American has been wary of being isolated from markets and sources of finance outside South Africa. This led to yesterday's decision to reintegrate Minorco and move the domicile of the entire company to London.