The Baume Brothers opened a branch in London, allowing the brand to expand throughout the British Empire and Far Eastern markets including India, Australia, and New Zealand. At the time, England was particularly attentive to chronometry, since exact time measurement provided strategic precision in both commercial and military maritime operations. This pioneering choice, reflecting the spirit of the House, would allow Baume & Mercier to become renowned for its watchmaking savoir-faire.

In the late ’40s, Baume & Mercier launched one of its great successes: the Marquise, a watch design that revolutionized women’s post-war watch fashion. Carried forward by this momentum, the Brand produced women’s watches of exquisite creativity and incredible modernity, proving that a ladies’ timepiece could be much more than just a miniaturized, somewhat oversimplified interpretation of a men’s watch. A technical achievement of its time in the service of jewelry watches, the Marquise featured a case linked by invisible hinges to the ends of the two curved bracelet links. Whether equipped with the Lépine caliber or nestled within a hunter case, whether plain or bejeweled, the Marquise was the epitome of the jewelry watch at the time. Released in several versions – gem-set or topped with an openworked dial cover –, it remained Baume & Mercier’s best-selling watch until the 1960s, establishing the Brand’s reputation in the field of ladies’ jewelry watches.

When Baume & Mercier adopted the Greek letter Phi – symbol of the Golden Ratio, divine proportions, and natural balance – in 1964, the Brand solidly established the spirit of design as part of its DNA. Since then, the emblem has appeared on all the Brand’s pieces. Its shape watches, imbued with bold, unbridled creativity and visually assertive in design, follow the structural and stylistic principles that aspire to perfection. They are based on ideal proportions, precise lines, meticulous attention to detail, and a subtle harmony of materials and colors. A few years later, the House took inspiration from the emblem of perfection to introduce the Symbol collection. That was its first concrete application of the Greek letter Phi. Designed beginning in 1965 and sold for the first time in 1967, these watches remained in the Brand’s catalog until the mid-1990s. In the 2000s, the Design Studio became the embodiment of Baume & Mercier’s creativity, applying the notion of Golden Ratio in the development of its most emblematic pieces.

In 1971, Baume & Mercier launched the Tronosonic collection. These models were equipped with a tuning fork movement, the predecessor of the quartz movement that would transform the watch industry a few years later. Once again, the Brand was demonstrating its pioneering spirit and its intention to equip its timepieces with the most advanced technology available, offering precision on a par with the best mechanical movements of the time.

After developing the innovative technology of the Tronosonic in 1971, Baume & Mercier dropped a stylistic bomb in 1973. The unique design of the Riviera, created by Jean-Claude Gueit, is based on the idea of turning a circle into an unconventional shape by connecting the twelve numerals on the dial with straight-edged segments that delineate the outline of the case. With its emblematic name, evoking elegance and leisure, the Riviera won over a new clientele seeking avant-garde style, becoming the Brand’s flagship model for years to come. At a time when dress watches were invariably crafted in gold, Baume & Mercier initially opted for the strength and elegance of steel, to bring forth a watch that could go from the city to weekend sports. As the years went by, it brought forth gold and bicolor versions in addition to jeweled pieces.