Cartier Diadea Diamond 18K Yellow Gold Engagement / Cocktail / Band Ring

With its three intertwined bands, Cartier’s Trinity ring feels both modern and classic. Originally designed in 1924, the design was a minimalist outlier in an era dominated by the ornamentation of the Art Deco aesthetic. Designed by Louis Cartier (1875–1942), the grandson of the legendary French jewelry house’s founder, he chose three unadorned 18-karat gold bands for the Trinity ring, employing only their varied hues — white, pink and yellow — and the simple Cartier stamp for decoration.

The Trinity ring is rich with symbolism, with each of the bands representing a different phase of a relationship: the white stands for friendship, the pink for love and the yellow for fidelity. According to jewelry lore, the Trinity ring was inspired by poet, novelist and filmmaker Jean Cocteau, who reportedly dreamed of Saturn’s rings one night and asked Cartier to design a ring inspired by them. Whether or not that’s true, Cocteau did wear the ring on his pinkie finger, elevating it to a certain level of stardom.

Over the years, Cartier’s Trinity collection has grown to include various versions of the original ring, some of which feature the original three bands outfitted with diamonds or colored gemstones of different shapes and styles. There was even an iteration with diamond stars, which debuted on the catwalk of 3.1 Phillip Lim’s Fall 2009 show. Other models have different colored bands — a black ceramic band paired with two white-gold ones, for example — and silhouettes, such as three stacked bands instead of intertwined ones.

The Trinity collection includes Trinity bracelets, earrings and necklaces, but the Trinity ring remains the most recognizable piece in the series. It has joined the ranks of Cartier’s most renowned successes, such as the Panthère de Cartier bracelet, originally purchased by the Duke of Windsor for his wife, the Duchess of Windsor, in the 1950s, and the chastity belt–inspired Love bracelet, designed by Aldo Cipullo in 1969.

For its extraordinary range of bracelets, watches, rings and other adornments, French luxury house Cartier is undeniably one of the most well known and internationally revered jewelers in the world among clients both existing and aspirational.

Perhaps 1847 was not the ideal time to open a new watchmaking and jewelry business, as the French Revolution was not kind to the aristocracy who could afford such luxuries. Nevertheless, it was the year Louis-François Cartier (1819–1904) — who was born into poverty — founded his eponymous empire, assuming control of the workshop of watchmaker Adolphe Picard, under whom he had previously been employed as an assistant. Of course, in the beginning, it was a relatively modest affair, but by the late 1850s, Cartier had its first royal client, Princess Mathilde Bonaparte, niece of Napoleon Bonaparte, who commissioned the jeweler to design brooches, earrings and other accessories.

Under the leadership of Louis-François’s son, Alfred, who took over in 1874, business boomed. Royalty around the world wore Cartier pieces, including Tsar Nicholas II of Russia, the Maharaja of Patiala and King Edward VII, who had 27 tiaras made by the jewelry house for his coronation in 1902 and issued Cartier a royal warrant in 1904. (Today, the British royal family still dons Cartier pieces; Kate Middleton, Duchess of Cambridge, regularly sports a Ballon Bleu de Cartier watch.)

Cartier’s golden years, however, began when Alfred introduced his three sons, Louis, Pierre and Jacques, to the business. The brothers expanded Cartier globally: Louis reigned in Paris, Pierre in New York and Jacques in London, ensuring their brand’s consistency at their branches across the world. The trio also brought in such talents as Charles Jacqueau and Jeanne Toussaint.

One of Cartier’s earliest major successes was the Santos de Cartier watch — one of the world's first modern wristwatches for men. (Previously, a large number of people were using only pocket watches.) Louis designed the timepiece in 1904 for his friend, popular Brazilian aviator Alberto Santos-Dumont, who wanted to be able to check the time more easily while flying.

Cartier’s other famous timepieces include the Tank watch, which was inspired by the linear form of military tanks during World War I, and the so-called mystery clocks. Invented by watchmaker and magician Jean-Eugène Robert-Houdin and later crafted exclusively for Cartier in the house’s workshop by watchmaker Maurice Couët, the mystery clocks were so named because the integration of glass dials on which the clocks’ hands would seemingly float as well as structures that are hidden away within the base give the illusion that they operate without machinery.

On the jewelry side of the business, Cartier’s internationally renowned offerings include the Tutti Frutti collection, which featured colorful carved gemstones inspired by Jacques’s trip to India and grew in popularity during the Art Deco years; the panthère motif, which has been incorporated into everything from brooches to rings; and the Love bracelet, a minimal, modernist locking bangle inspired by medieval chastity belts that transformed fine jewelry.

While the Cartier family sold the business following the death of Pierre in 1964, the brand continues to innovate today, renewing old hits and creating new masterpieces.

Find contemporary and vintage Cartier watches, engagement rings, necklaces and other accessories on 1stDibs.