Made in Mzansi: Sold to the world as forever

Ask AI 6minIn 1999, Advertising Age named “A Diamond Is Forever” the advertising slogan of the 20th century.

From the Kimberley diamond fields and Cecil John Rhodes’s empire-building ambitions to one of advertising’s most enduring slogans, De Beers has a distinctly South African origin story. Now, as the diamond giant faces a change of ownership, its next chapter is being negotiated.

Long before “A Diamond Is Forever” became one of the world’s most recognisable advertising slogans, a young British immigrant was making his fortune in the diamond fields of Kimberley in the Northern Cape. His name was Cecil John Rhodes, and the company he helped build would go on to shape the global diamond industry.

De Beers is now at the centre of a major ownership transition. Anglo American, which owns 85% of the diamond company, put De Beers up for sale in 2024 as part of a wider restructuring of its mining interests. Botswana owns the remaining 15%.

In November 2026, Botswana President Duma Boko announced that the country would double its stake to 30% under a proposed transaction involving the Global Diamond Consortium, led by former De Beers chief executive Gareth Penny.

The consortium has been selected as Anglo American’s preferred bidder. Namibia and Angola have also been associated with the proposed regional ownership structure, although their precise roles remain subject to final agreements.

The transaction has not yet been finalised, with binding agreements still to be negotiated.

Cecil John Rhodes arrived in South Africa in 1870, aged 17.

Rhodes arrived in South Africa in 1870, aged 17, initially managing his brother’s cotton farm in Natal. But it was the discovery of diamonds in the Northern Cape that would change the course of his life – and the country’s mining history.

The first recorded diamond discovery in the region was made by Erasmus Jacobs near Hopetown in 1867. In 1871, diamonds were discovered on the farm Vooruitzicht, which belonged to the De Beer brothers. The discoveries helped spark the Kimberley diamond rush, drawing thousands of prospectors and entrepreneurs to the area.

Rhodes entered the diamond business, buying claims and building up his interests with business partner Charles Rudd. He recognised that the future of the industry lay in consolidating ownership of the mines rather than allowing production to remain fragmented among hundreds of individual operators.

His ambition brought him into competition with another powerful diamond entrepreneur, Barney Barnato, who controlled the Kimberley Central Diamond Mining Company.

The consolidation of competing mining interests gathered pace through the 1880s, involving several companies and financiers. On 12 March 1888, De Beers Consolidated Mines was established, with Rhodes as its first chairman. The company brought major diamond mining interests under one roof and laid the foundations for its growing influence over the industry.

The name came from the De Beer brothers, whose farm had become central to the diamond discoveries.

One of Cecil John Rhodes' most famous ambitions was the Cape-to-Cairo railway – a north-south route that would connect the southern tip of the continent with Egypt through British-controlled territory.

Diamonds were only part of Rhodes’s ambitions.

He became prime minister of the Cape Colony in 1890 and pursued an expansionist vision of British imperial control across Africa. One of his most famous ambitions was the Cape-to-Cairo railway – a north-south route that would connect the southern tip of the continent with Egypt through British-controlled territory.

The plan was never completed, but it became one of the defining symbols of Rhodes’s imperial ambitions. He also wanted the route connected by telegraph, creating a line of communication across the continent.

His vision was tied to the expansion of British power, not simply a transport project. Rhodes’s role in colonial expansion, including the establishment of the British South Africa Company and the seizure of African land and political authority, remains a deeply contested part of South African history.

His diamond wealth helped finance his political ambitions, while his business interests grew alongside the expansion of British influence in southern Africa.

Rhodes died in 1902, but the company he helped establish continued to expand its reach.

Ernest Oppenheimer, who had founded Anglo American in 1917, became a major shareholder in De Beers in the 1920s.

Another name would become closely associated with De Beers.

Ernest Oppenheimer, who had founded Anglo American in 1917, became a major shareholder in De Beers in the 1920s. He joined its board in 1926 and became chairman in 1929.

Under Oppenheimer, De Beers strengthened its influence over the global diamond trade, developing a system for controlling the supply and distribution of rough diamonds. The company became synonymous with the industry, with its influence extending well beyond the mines in which it operated.

For much of the 20th century, De Beers played a central role in determining how diamonds reached the market and how they were sold.

But its most enduring influence may not have come from mining or trading. It came from advertising.

In 1947, American copywriter Frances Gerety, working for the advertising agency N.W. Ayer, came up with a line for De Beers that would become one of the most successful slogans in advertising history.

Underground in the Kimberly mine. De Beers has long since grown beyond its Kimberley origins. Its operations span diamond exploration, mining, trading, jewellery brands and synthetic diamond technology.

The slogan first appeared in De Beers advertising in 1948. It helped establish the diamond engagement ring as a symbol of lasting love and commitment, particularly in the United States, where the company was seeking to build demand for diamonds.

The marketing was carefully constructed. Diamonds were positioned as something that should be kept, rather than sold or traded, and as the natural expression of a lifelong commitment.

It was a powerful commercial idea. De Beers was no longer simply selling a precious stone. It was selling what the stone was supposed to represent.

In 1999, Advertising Age named “A Diamond Is Forever” the advertising slogan of the 20th century The phrase remains closely associated with De Beers almost eight decades after Gerety wrote it.

The Big Hole in Kimberly: the natural diamond industry faces significant challenges. Weaker demand, falling prices and competition from laboratory-grown diamonds have put pressure on producers and retailers.

De Beers has long since grown beyond its Kimberley origins. Its operations span diamond exploration, mining, trading, jewellery brands and synthetic diamond technology.

It operates mines in Botswana, Canada, Namibia and South Africa, with its business increasingly shaped by partnerships with the governments of the countries in which it operates.

Its relationship with Botswana is particularly important. De Beers and the Botswana government established Debswana in 1969 as an equal partnership to develop the country’s diamond resources. Botswana has since become central to the company’s production and commercial future.

But the natural diamond industry faces significant challenges. Weaker demand, falling prices and competition from laboratory-grown diamonds have put pressure on producers and retailers.

Diamond ratings rely on the 4Cs – Colour, Clarity, Cut, and Carat Weight – which provide a universal standard for evaluating a stone's quality and value

If completed as proposed, Botswana would become De Beers’ largest single shareholder, giving one of the world’s most important diamond-producing countries a greater say in the future of the company.

It would be a significant new chapter for a business established in Kimberley in 1888, when Rhodes and other mining interests helped consolidate competing diamond operations.

The man who helped build the company had once imagined connecting Africa from the Cape to Cairo under British rule. More than a century later, the company bearing the name of a Kimberley farm is negotiating a future in which African diamond-producing countries could have a much greater stake in its ownership.

And the slogan that helped make diamonds forever is still doing its work.