Swiss Haute Horlogerie manufacturer Audemars Piguet unveils the Royal Oak Perpetual Calendar Openworked “150th Anniversary” limited edition. As the final timepiece to feature Calibre 5135, it marks the end of an era for the movement that has powered the brand’s 41mm openworked selfwinding perpetual calendar watches for nearly a decade.
Before diving into the new release, let’s take a moment to revisit the history of Audemars Piguet’s perpetual calendars—a legacy that began in 1978. In the dawn of the 1970s, at the height of the quartz crisis, Audemars Piguet released the thinnest selfwinding perpetual calendar wristwatch of its time equipped with the ground-breaking Calibre 2120/2800.
Conceived in secret by three dedicated watchmakers, this perpetual calendar movement set new industry standards, ushering a significant era of growth for the company. Over the next 18 years, the Manufacture produced, cased and sold more than 7,000 movements, reviving other classic complications along the way, including the openworked chronograph (1980), the first selfwinding tourbillon (1986), the minute repeater (1992) and the Grande Complication combination (1996). In 1984, Calibre 2120/2800 made its debuts in the Royal Oak collection (Model 5554), and an openworked version was introduced two years later (Model 25636). Although the production of perpetual calendar wristwatches was well underway, the company continued to create avant-garde and classical pocket watches with this complication too.
Building on its predecessor’s legacy, Calibre 5134 was launched in 2015, adapting the perpetual calendar movement to a larger 41 mm case diameter while maintaining a thin 4.5-mm profile. It was housed in a new Royal Oak model, ref. 26574, bringing renewed attention to a complication whose popularity had been in decline since 1989. This revival was confirmed in 2017 with the launch of a black ceramic animation causing a sensation (ref. 26579CE)
Combining the ancient art of openworking with cutting-edge technology, Calibre 5135 was released in 2019 to power the Royal Oak Perpetual Calendar Openworked in black ceramic (ref. 26585CE), revealing the movement’s refined decorations from both the front and the back of the watch. This calibre has since then equipped various iterations, including an 18-carat white gold model set with 962 diamonds (ref. 26625BC) and a collaboration with Cactus Jack (ref. 26585CM) in 2023, as well as the Frosted Gold (ref. 26585BC) in 2024. After nearly a decade, this movement takes its final bow in a limited edition dedicated to celebrating the brand’s 150 years of fine watchmaking.
The new Royal Oak Perpetual Calendar Openworked “150th Anniversary” limited edition.
The new Royal Oak Perpetual Calendar Openworked “150th Anniversary” is inspired by reference 25729, the perpetual calendar pocket watch created in 1992 and now exhibited in the Musée Atelier Audemars Piguet. The new model features a 41mm case and bracelet crafted from a combination of titanium and Bulk Metallic Glass (BMG). BMG, used for the bezel, caseback frame, and bracelet studs, has been mirror-polished to enhance its distinctive glow, while the titanium surfaces feature a satin-brushed finish with polished chamfers for added contrast.
Discovered in the 1960s, BMG is now used in applications as diverse as micro-electronics and golf. Produced in hundreds of different variations, this alloy shares several characteristics with other glasses when cooled rapidly, an essential step that prevents crystals from forming and freezes the material in a glassy state lending it strong, amorphous properties. Audemars Piguet has co-developed its own palladium-based BMG, composed of over 50% palladium, making it highly resistant to wear and corrosion with a glossy lustre. The Manufacture first coupled titanium with BMG for the one-of-a-kind Royal Oak “Jumbo” Extra-Thin timepiece (ref. 15202XT) created for Only Watch in 2021, which also inaugurated the use of palladium-based metallic glass in watchmaking. BMG was further introduced to the Royal Oak’s “Jumbo” (ref. 16202XT) line two years later, before adorning a Royal Oak Perpetual Calendar (ref. 26585XT) in 2024.
Subtle design codes were specially conceived for the celebration, including a vintage “Audemars Piguet” signature inspired by historical documents, inserted in the moon-phase subdial at 6 o’clock.
The new Royal Oak Perpetual Calendar Openworked is limited edition of 150 pieces and priced at €221,100 (daily rate).
More details about Audemars Piguet watches find on www.audemarspiguet.com
