The 25829BA is the Royal Oak QP Skeleton in yellow gold, the second generation of skeletonized RO QP and the first with a leap year indication. Introduced in 1996 and produced in small batches through roughly 2009, it captures a very specific moment: Switzerland emerging from the quartz crisis with...

Few watches encapsulate the 1970s luxury sports movement like the Vacheron Constantin 222, launched in 1977 to mark the maison's 222nd anniversary. While Gérald Genta drew the Royal Oak and Nautilus, the 222 came from a young Jorg Hysek. The range spanned the 37mm 'Jumbo' ref. 44018, this 34mm midsize...

When A. Lange & Söhne numbered its early Lange 1s, the reference told you how the watch was delivered: 101-series watches came on alligator, while 151-series watches wore an integrated precious-metal bracelet manufactured by Wellendorff. The ref. 151.021—yellow gold with champagne dial and a matching gold bracelet—is the bracelet counterpart...

Patek Philippe’s first serially produced Tourbillon also happened to be a Minute Repeater. That’s not even the most astonishing thing about the ref. 3939, though, as when it was introduced in 1992 it came to market at just 33mm. The manual calibre RTO-27-PS took up the entire caseback, with little...

The reference 25668BA is Audemars Piguet's Openworked Quantième Perpétuel in yellow gold, and the most expressive of a bloodline that begins with the 5548 of 1978. Where the 5548 introduced the thinnest self-winding perpetual calendar the world had seen to revive mechanical watchmaking in Switzerland, the 25668 stripped the movement...

Patek Philippe's 5004 is the apex of the Lemania-ébauche era—the first production Perpetual Calendar Split Seconds Chronograph, a watch Philippe Stern reportedly cast as the 'spiritual successor to the 2499.' But within that already-rarefied run, the black-dialed examples occupy their own tier, and in pink gold they are one of...