Audemars Piguet 25554BA Royal Oak Perpetual Calendar 18K Yellow Gold Champagne Dial RARE

This Audemars Piguet Royal Oak Perpetual Calendar ref. 25554BA, introduced circa 1985–1986, represents one of the earliest and most historically significant integrations of a perpetual calendar into the iconic Royal Oak line. Crafted in 18K yellow gold, the 39 mm case houses the ultra-thin automatic Caliber 2120/2800, a marvel of horological engineering that enabled a mere 7.5 mm thickness—remarkably slim for a self-winding perpetual calendar of its era. With a champagne dial offering recessed subdials for day, date, month, and moonphase, the aesthetic is both balanced and elegant. Production was extremely limited—approximately 223 examples in yellow gold—making it a rare and highly coveted piece among collectors. The Gerald Genta–designed octagonal bezel and integrated bracelet underscore its design pedigree and continuity with the original Royal Oak ethos. This reference stands as a technical and stylistic milestone: a vintage complication in a sporty-luxury format, combining mechanical finesse, design heritage, and scarcity in one compelling package. Like New with Audemar Piguet winder box, and Extract from the Archives dated 1985. Includes Audemars Piguet service papers dated 2021.