Ernest Oppenheimer

Sir Ernest Oppenheimer (22 May 1880 – 25 November 1957) was a diamond and gold mining entrepreneur, financier and philanthropist, who controlled De Beers and founded the Anglo American Corporation of South Africa.
Career.
He was born in Friedberg, Hesse, Germany, the son of Edward Oppenheimer, a cigar merchant. Oppenheimer began his working life at 17, when he entered Dunkelsbuhler & Company, a diamond brokerage in London. His efforts impressed his employer and in 1902, at the age of 22, he was sent to South Africa to represent the company as a buyer in Kimberley, where he eventually rose to the position of mayor from 1912 to 1915. In this role, he helped raise the manpower for the Kimberley Regiment for service during World War I.
He became great friends with William Lincoln Honnold, an American engineer and chairman of Transvaal Coal Trust, Brakpan Mines, Springs Mines and The New Era Company.
In 1917, they launched the Anglo American Corporation with financial assistance from J. P. Morgan. The initial capital was £1 million. Half of the capital was subscribed in America and half in England and South Africa. He would remain as a permanent director and its chairman until 1953. In 1919, two years after its launch, Anglo American purchased diamond mines in South West Africa which would pose a challenge to the De Beers diamond business monopoly.
He took part in the 1924 South African general election and was elected to the House of Assembly as the Member for Kimberley. He held the seat until 1938. In 1927, Ernest Oppenheimer managed to wrest control of the late Cecil Rhodes' De Beers empire and built and consolidated the company's global monopoly over the world's diamond industry until his retirement. He gained the chairmanship of De Beers in 1929.
He was involved in a number of controversies, including price fixing, antitrust behaviour and an allegation of not releasing industrial diamonds for the US war effort during World War II.
Personal life.
He married Mary Lena Pollak in 1906 and had two sons. She died in 1934. In 1935, he married Caroline Magdalen Oppenheimer (nee Harvey) widow of Michael Oppenheimer.
He died in Johannesburg in 1957. He was born into a Jewish family, but, as an adult, he converted to Anglicanism and was buried at St George's Church, Parktown. He was succeeded in the business by his son, Harry Oppenheimer. Oppenheimer's brother, Sir Bernard Oppenheimer, was also heavily involved in the diamond industry.
Legacy.
In 1964, the Oppenheimer Diamond was named in his honour by its owner, Harry Winston, who donated the stone (not a gem, as it remains uncut and unpolished) to the Smithsonian Institution as a memorial.