Why a Diamond? The Making of a Promise

For most of history, a diamond had nothing to do with love. The engagement ring we now take for granted is younger than the light bulb — and its story runs from a Habsburg archduke to a single sentence written late one night in a Philadelphia office.

A ring in the shape of an M

The first diamond engagement ring on record was not a tradition — it was a grand gesture. In 1477, Archduke Maximilian of Austria proposed to Mary of Burgundy with a slender gold band set with thin, flat diamonds arranged in the shape of an M. The ring survives to this day in Vienna. Diamonds were then so rare that only royalty could dream of them, and the idea of a commoner proposing with one would have seemed absurd.

Rings themselves were far older. Ancient Romans exchanged betrothal rings of iron and later gold — a public sign that a promise had been made. But the stone was incidental. For centuries after Maximilian, a diamond stayed a symbol of dynasty and wealth, not a near-universal rite of engagement.

The line that changed everything

What turned the diamond into the engagement stone was not romance but marketing — and a stroke of genius. In 1947, a copywriter named Frances Gerety, working at the N.W. Ayer agency for the diamond house De Beers, scribbled four words before going to bed: “A Diamond Is Forever.”

The slogan did something no advertising had done before: it fused the hardness of the stone with the permanence of love, and made a diamond feel less like a luxury than a necessity. In 1999, Advertising Age named it the single greatest slogan of the twentieth century. Within a generation, the diamond engagement ring went from a privilege of the few to an expectation for nearly everyone.

What the story really tells us

Knowing the history doesn’t cheapen the ring — it clarifies it. The meaning of an engagement ring was never in the rarity of the stone or the size of the bill. It was in the gesture: a durable, beautiful thing, chosen and given as a promise meant to last.

That is exactly why a lab-grown diamond changes nothing about the sentiment and everything about the freedom. The same fire, the same forever — now chosen on your own terms, at a scale that serves the promise rather than the price tag.

Sources: Kunsthistorisches Museum, Vienna, on the 1477 Maximilian–Mary of Burgundy ring; American Gem Society, on the history of the diamond engagement ring; The Drum and Sotheby’s, on De Beers, Frances Gerety and “A Diamond Is Forever” (named the top slogan of the century by Advertising Age, 1999).

Keep reading: why the ring goes on the fourth finger, and how to choose a ring that outlasts the wedding.