Perpetual calendars are the authoritative complications of calendar watches. When created the Quantieme PerpetualAutomatiquein the late 70s, perpetual calendars were scarce. Upon its release in 1978, the Quantieme Perpetual represented one of the most significant horological innovations of the period - introducing the worlds thinnest, self-winding perpetual calendar movement. It achieved its ultra-slim profile (3.95 mm) by adapting the renowned calibre 2120 movement, launched in 67.

In 1875, Jules Louis Audemars and Edward Auguste Piguet founded the Swiss watch manufacturing company Audemars Piguet in Le Brassus, Valle de Joux. In 1955, the brand began production of its first series of perpetual calendar wristwatches to feature a leap year indication. A specialist in the manufacture of complications since it was established, Audemars Piguet continued to produce a variety of high-quality perpetual calendars throughout the late 70s to the early 2000s, considered some of the most impressive of the modern era.

This rare white gold example perfectly illustrates why the Quantieme Perpetualseemsso under-appreciated. Understated both in styling and size - modest (by today's standards) at 36 mm - with aslim case matched by an ultra-thin, automaticperpetual calendar movement. The white goldcase features a stepped bezel and short, down-turned lugs, which work proportionately well together. On the reverse, the watch is features circular graining, along with finely-engraved markings.

The sub-dial at 3 o'clock shows the date, in a slightly recessed sub-register, giving depth to the otherwise smooth white dial. In a similar fashion, the days of the month are placed at 9 o'clock, with the months of the year at 12. Themoon-phase is placed at six o'clock, with graduation for moon age above. The white dial is further accented with applied index markers - corresponding harmoniously with Audemars Piguets stick hands. The index markers and hands are subtle in form, with excellent legibility against the white backdrop. The lacquer finish on the subdials displays some light crackling resulting from age,visible at certain angles.

This Quantieme Perpetual Automatique ref.25548BC is powered by the AP caliber 2120, derived from Jaeger-LeCoultres legendary ultra-thin JLC 920 calibre movement. The caliber 2120 was an initial project of Jaeger LeCoultre in 1967, funded and contributed by Audemars Piguet, and famous for its adoption by Audemars Piguet, Patek Philippe and Vacheron Constantin. The ultra-thin automatic 2120calibre features 38 working jewels, Gyromax balance and four ruby wheels to support the full-diameter rotor, which runs on a beryllium rail for stability. The rotor is decorated with Genevan stripes and edged with 21-carat gold, to increase the oscillating mass. The AP calibre 2120 remains the thinnest full-rotor self-winding movement in the world, considered by many as one of the most technically refined wrist-watch movements ever made.

The watch comes fitted to one of our prototype grey suedestraps and is accompanied by its original white goldtang buckle.It comes withan Extract from the Archives (to follow).

Viewings can be arranged in Central London by appointment.

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