South Africa's two richest men are locked in a decades-long horse racing rivalry

South Africa's two wealthiest families have spent eight decades competing in a business that has nothing to do with diamonds or wristwatches. The Ruperts and the Oppenheimers breed racehorses, and they have poured billions of rand into the sport, built rival stud farms that dominate it, and twice pulled it back from collapse.

Johann Rupert, the 75-year-old chairman of the Swiss luxury group Richemont, is worth $16.1 billion and ranks as Africa's second-richest person behind Aliko Dangote. Nicky Oppenheimer, 80, whose family controlled De Beers for 85 years, is worth $10.6 billion and sits fourth on the continent.

Neither man runs the horses. Gaynor Rupert owns Drakenstein Stud. Mary Slack, Nicky Oppenheimer's sister, runs Mauritzfontein and Wilgerbosdrift.

The Oppenheimers got there first. Harry Oppenheimer and his wife, Bridget, bought Mauritzfontein in 1945, a farm 15 minutes from Kimberley that had served as a remount station for the British Army during the Boer War. Kimberley was De Beers headquarters, and Harry held the town's parliamentary seat from 1948 to 1957. He took over Anglo American and De Beers only after his father, Sir Ernest, died in 1957.

Bridget became the face of the operation. She designed the black-and-yellow silks that the family still races in, and the couple came to be known as the mother and father of South African horse racing.

Money in the sport sits in breeding rather than racing. A horse runs to prove what its genes are worth, and Mauritzfontein set out to own the best of them. Janus, a top-class French racehorse, arrived as its first imported stallion in 1951. Fort Wood, a Group 1-winning son of Sadler's Wells, followed in 1994.

Fort Wood's first runner settled the argument. Horse Chestnut, foaled in 1995 and bred and owned by Harry and Bridget, won the Cape Guineas by six and three-quarter lengths in January 1999, then beat older horses by eight and a quarter lengths in the J&B Met three weeks later, the first three-year-old to take that race in 54 years. He won the SA Classic in March and the SA Derby by about 10 lengths in April, completing the Triple Crown, and was named Horse of the Year.

He won eight of his nine South African starts and was never beaten after his juvenile season. Sent to the United States, he ran once, winning the 2000 Broward Handicap at Gulfstream Park before an injury ended his career. He stood at Claiborne, sired nine stakes winners, and his progeny earned $8.6 million.

Then the rivalry produced its strangest chapter. Horse Chestnut returned to South Africa in 2009 and spent his final years standing at stud at Drakenstein, the Ruperts' farm. He died there in February 2015, aged 19, of heart failure. Gaynor Rupert said afterward that it had been a privilege to stand a horse of such importance to South African racing.

Drakenstein was built from nothing. Gaynor Rupert, born Gaynor Fairhurst, established it in the early 2000s across 130 hectares on the lower slopes of the family's L'Ormarins wine estate near Franschhoek, with the Groot Drakenstein mountains behind it.

The Ruperts skipped the slow route. Rather than assemble a broodmare band over generations, they went shopping internationally and formed syndicates to buy stallions outright, among them the American-bred Trippi, What A Winter, Futura and Duke of Marmalade. Their horses run in blue and white.

The approach compressed decades into years. Drakenstein has bred 18 individual Grade 1 winners. In the 2022-23 season it was named Equus Champion Breeder, Outstanding Breeder and Champion Owner, and its horses won the Durban July, the Cape Town Met, the Cape Guineas, the Cape Derby and, with some irony, the H.F. Oppenheimer Horse Chestnut Stakes. Drakenstein bred seven of the runners in that year's July, including the horses that finished first and second.

Covering fees for the Ruperts' stallions have been reported at between roughly $3,700 and $7,400 (60,000 and 120,000 rand).

The Oppenheimer operation passed to the next generation. After Harry and Bridget died, their daughter Mary took over. She married out of the family name and races as Slack, keeping the historic silks, and now runs Mauritzfontein alongside Wilgerbosdrift as a single breeding venture, with her daughter Jessica Jell managing the older farm. The combination bred six Grade 1 winners across three recent seasons and produced 39 stakes winners.

Both families have paid to keep the industry alive. When the pandemic shut racing down, they injected a reported $6.1 million (100 million rand) between them, covering betting stakes out of their own pockets and paying the salaries of trainers, grooms and jockeys. Slack went further, backing the creation of 4Racing to restructure the sport. The Ruperts spent millions renovating Kenilworth in Cape Town, where the L'Ormarins King's Plate and the Cape Town Met are run.

Their steadiness outlasted others. Markus Jooste, the Steinhoff chief executive, became one of the sport's dominant owners before the retailer's accounting fraud unravelled in 2017 and took his racing empire with it.

What remains is a competition that neither family appears interested in winning outright. They breed against each other, race against each other, and between them keep the sport standing.