Barney Barnato was born in 21 February 1851, Whitechapel slum of London. His original name was Barnett Issacs but changed it to Barney Barnatto when he was acting as a comedian. He followed his brother Harry to Cape Town in 1873 to seek fortune in the diamond rush that followed the 1866 discovery of diamond in Kimberly. He came to South Africa penniless, but within 10 years he was a millionaire and the Barnato Diamond Mining Company that he helped set up was a competitive rival of Cecil John Rhodes’ De Beers company.
Rhodes and Barnato set out to dominate the diamond industry by trying to buy up all the shares that came onto the market. Their struggle for control of the only other independent company, 'The French Company' (Compagnie Francais des Mines de Diamant du Cap), was acute, until Barnato merged all his diamond interests in the Kimberley Central Diamond Mining Company and became the owner of the French company. But his victory soured when he learned that Rhodes had managed, through the backing of the Rothschilds and Alfred Beit, to get control of one-fifth of Kimberley Central Mine for himself. Share prices soared as Rhodes tried to outwit his competitor by enticing Barnato's shareholders to sell to his agents. Barnato could not prevent this. The story can be dismissed that Rhodes, after a weary twenty-eight hours of negotiation, suddenly produced a bucket heaped with diamonds. 'Sign, Barney, and it's all yours,' Rhodes is supposed to have said.
In 1888, after much hard bargaining, Barnato capitulated. 'You can't win me with bribes.' Barnato is reputed to have said, 'But you have your fancy, as other men have theirs, and I see that I shall have to give you the means to go North.’ And sign he did, agreeing that the new company's profits could be used for British imperialistic expansion. Rhodes gained Barnato's support to amalgamate the two companies as De Beers Consolidated Mines Ltd. by promising to make him one of the four life-governors, by arranging for him to be elected as a member of the Cape Assembly, and by procuring him membership to the exclusive Kimberley Club. Rhodes paid £5,38,650 for the Kimberley Central Diamond Mining Company: four million went into the pockets of the Barnato Brothers and Barney became Kimberley's MP in the Cape Parliament from 1889 to 1897
Barney Barnatto committed suicide on his way to London. He jumped off the boat and drowned himself in 14 June 1897.