What makes a watch legend?

Aurel Bacs, industry veteran and senior consultant at Phillips auction house, says it takes relevance, boldness and a kind of mystique. “Something cannot be iconic just because a few nerds or scholars in a back office agree that it’s important,” Mr. Bacs said. “It needs a following; it needs recognition.”

Sounds like the Audemars Piguet Royal Oak, the watch with an octagonal bezel and eight distinct screws that is celebrating its 50th anniversary this year. The watch’s innovative design and groundbreaking use of stainless steel as a precious material, the work of the designer Gerald Genta, has been generally credited throughout the industry as spawning the luxury sports watch category.

Gianni Agnelli, King Juan Carlos of Spain and Karl Lagerfeld were early adopters (the designer wore a customized all-black model in 1979). In more recent times, the musicians and well-known watch fans John Mayer and Ed Sheeran have worn Royal Oaks on tour; rappers including Jay-Z and Rick Ross have rhapsodized about Audemars Piguet in their songs, and basketball stars including LeBron James and Steph Curry all have worn Royal Oaks, as have the actress Millie Bobby Brown and the model Kylie Jenner. And recently, the prime minister of Cambodia, Hun Sen, was spotted wearing a complicated Royal Oak Offshore model.

“It never surprises me any more who is seeking an Audemars Piguet Royal Oak,” said Rob Ronen, who has been selling the watch for nearly 20 years and is co-founder of the New York City-based retailer Material Good, an Audemars Piguet authorized dealer. “It doesn’t ostracize any group of people — of any gender, any race, any culture. It really translates across all bounds.”

Its versatility helps, too, he said: “You can see a Royal Oak on the beaches of St.-Tropez, St.-Barts, Amalfi Coast, where people are having lunch in their swim shorts. At the same time, that same piece can be put with a tuxedo.”

If you can get one, that is. As Audemars Piguet, Rolex, Patek Philippe and Richard Mille have continued to strengthen their dominance of the luxury Swiss market in recent years, the Royal Oak has become ever more difficult to obtain. Potential buyers have said new ones are nearly impossible to find while, on the secondary market, the Royal Oak is trading at 85 percent above retail value according to research by the Business of Fashion online platform and McKinsey & Company.

And while neither of the family-controlled brands Audemars Piguet or Patek Philippe release sales figures, a recent report by Morgan Stanley estimated that Audemars Piguet outpaced Patek Philippe for the first time in 2021 — moving it into fourth place in Swiss watch performance, following Rolex, Cartier and Omega.

Game Changer

From Day 1, the Royal Oak attracted attention with its rule-breaking design, establishing a new era for luxury sport watches, watch specialists said.

The year was 1970, when the Japanese had only just begun to introduce the quartz watches that, as the decade progressed, would all but destroy the Swiss mechanical watch industry. Other forces were at play, too: A financial recession and energy crisis were looming, and culturally, the confluence of fashion, music, architecture and contemporary art were reshaping notions of design.

Audemars Piguet asked Mr. Genta to create a modern stainless-steel sports watch. The brand has records of a 1982 interview in which Georges Golay, managing director of Audemars Piguet at the time, recalled the brief: “We had to invent a model both sporty and stylish in spirit, suitable for evening wear and for the daily activities of today’s man of taste.” And the look had to match the watch’s Calibre 2121, which, at the time, was the world’s thinnest self-winding movement with a central rotor, just 3.05 millimeters thick.

Mr. Genta gave the Royal Oak the look of a vintage diving helmet, the hexagonal screws on the bezel inspired by the helmet’s bolts and, as the designer said, instantly evoking the watch’s 100-meter (328-foot) water resistance. The design was disruptive, experts have said: Until then, screws had always been hidden within the watch movement, not placed front and center.

He also added more geometry — the case was a tonneau, or barrel, shape with two bevels — that he integrated with a 154-piece steel bracelet, one of the most complex in watchmaking at the time.

Mr. Genta was a trained jeweler, something that was reflected in the Royal Oak’s contrast between mirror-polished and satin finishes, both done by hand. There also was the jewel-like dial featuring a pattern of small, truncated pyramids set among diamond-shaped holes, a guilloché style generally known as clous de Paris but Audemars Piguet calls tapisserie. In all, the varying finishes and dial engraving produced a play of light on the wrist.

The designer’s use of stainless steel was another game changer, the meticulous hand finishing elevating the industrial metal. “The material is not gold or platinum,” said Michael Friedman, head of complications at Audemars Piguet. “But through the work of artisanship, craft and finishing, it becomes this object of design — and it becomes far greater than the sum of its parts. It’s an expression of the men and women behind the bench.”

The notion was not only figurative: At its debut, the watch was priced at 3,300 Swiss francs, similar to gold watches at the time.

On April 15, 1972, the watch was introduced at the Basel fair, the annual event that for decades was the most influential stage in watchmaking. Jacqueline Dimier, Audemars Piguet’s first female watch designer, who joined the company in 1975, recalled the excitement it produced.

“No one could talk about anything else,” she wrote in an email. “We were all in admiration, no matter what brand we worked for. The Royal Oak was a U.F.O. in watchmaking and completely broke the design codes of the time.”

(Four years later, Mr. Genta would design the Nautilus for Patek Philippe, another seminal piece. Some collectors fiercely support their favorite — “It’s like dog and cat lovers,” Mr. Bacs said.)

Collectors gave the new Royal Oak the nickname Jumbo, its 39-millimeter size huge compared with the 34-millimeter to 36-millimeter sizes that were standard for men’s watches at the time. (Even Mr. Genta called the size “elephant-like,” although the dimension was required by the 28-millimeter diameter of the Calibre 2121 and the eight screws.)

The Royal Oak’s immediate success is still something of an urban myth in watchmaking circles as some figures from the time suggest a commercial flop: According to the company’s archives, in its first four years, the Royal Oak Ref. 5402 never accounted for more than 7 percent of Audemars Piguet’s total production, nor more than 6 percent of sales.

Mr. Friedman, however, added some context: In 1970, the house had promised suppliers that it would make 1,000 pieces of the Royal Oak, a volume it had never committed to before; typically it would make 25 units of a single model, or just one-offs.

“When you’re making 5,000 watches a year and committing to 1,000 of one model, that’s a major shift in approach,” Mr. Friedman said. Fewer than 100 people worked at the house at the time, and only a few dozen Royal Oaks were completed each month, he added. (By comparison, as of December 2021 the company employed 2,255 people worldwide, 1,456 of whom were based in Switzerland, and it has said it expects to make 50,000 watches this year.)

By the end of 1972, the brand had sold 490 Royal Oaks, making it the most successful single model since the company’s founding in 1875.

Boom Years

The original Royal Oak — model 5402 — was left unchanged until 1976, when Ms. Dimier was charged with feminizing the design.

“It wasn’t easy,” she wrote. “The watch was barely four years old, quintessentially masculine, and adapting the creation of the legendary Gerald Genta was a daunting prospect. My approach was to preserve its essential character as a timepiece and concentrate on the proportions.”

In 1976, the 29-millimeter Royal Oak II was introduced, with a 35-millimeter gold model the next year. Between 1977 and 1981, 27 new models were made: more gold and mixed metal pieces; new diameters and calibers, including quartz; and gem-set designs.

And sales increased. For example, company records show that more than 1,000 29-millimeter Royal Oak watches were produced in 1979; 423 were made in 1976. Germany and Italy were especially strong markets.

A Horological Canvas

The Royal Oak’s first complication, day and date indicators, arrived in 1983, with its first high complication, the perpetual calendar, landing a year later.

In 1993, the model spawned the 42-millimeter chronograph Offshore, which had an extreme-sport theme. And new gem-set pieces and stone dials such as lapis lazuli were added to the mix.

Sizes were explored during the ’90s, too. A 20-millimeter model called the Royal Oak Mini, slightly more than the diameter of a penny, became the smallest Royal Oak ever made. “You could literally find a Royal Oak for every wrist size,” Mr. Bacs said. (This year several auction houses, including Phillips and Ineichen Auctioneers in Zurich, have scheduled sales dedicated entirely to the Royal Oak.)

As the decade wore on, the Royal Oak emerged as the house’s foremost horological canvas, where movements and materials were tested, but always anchored by the watch’s original design codes. For example, there was a limited edition in the unusual blue-gray alloy tantalum, and, in 1997, a mix of steel and platinum for a 25-piece skeletonized perpetual calendar. (Last year one of those models sold at Phillips for 403,200 Swiss francs, or $434,240, more than five times its minimum sale estimate.)

The 25th birthday observance in 1997 became an ode to new complications, including a chronograph, a limited-edition tourbillon wound from the back (the only Royal Oak without a crown) and a Grande Complication incorporating a minute repeater, split-second chronograph and perpetual calendar, among other functions.

Audemars Piguet is one of the few remaining family-run, independent watchmakers in Switzerland (with its headquarters and museum in Le Brassus), and its desire for individuality was encapsulated in 2002 by another Royal Oak offshoot: the Royal Oak Concept collection, which played with technical advancements and unusual materials like alacrite, a cobalt-based alloy, and carbon. And last year its collaboration with Marvel placed a 3-D white gold figure of the Black Panther on the dial of a flying tourbillon, a limited edition of 250 pieces that sold out.

Alchemy of Past and Future

These contrasts and disruptions — steel elevated to luxury status, a superhero blended with the serious world of watchmaking — have continued to bolster the Royal Oak’s reputation. It’s “an alchemy that is contributing towards its success,” Mr. Friedman of Audemars Piguet said. “It’s like hearing a song that is new but familiar at the same time.”

Mr. Ronen, the New York dealer, agreed. “The Royal Oak is a design that’s timeless, but at the same time really modern, depending on how Audemars Piguet manipulates the materials.”

Yet by the Royal Oak’s 40th anniversary, the Offshore collection was stealing the limelight, partly because of collaborations with the likes of Jay-Z and Arnold Schwarzenegger (who created one for “End of Days”). Such associations again broke boundaries, now thrusting the Royal Oak into popular culture, and at a time in which celebrity tie-ins with the industry were still being developed.

The Royal Oak 15202, which had direct ties to the original model, suddenly looked dated, and François-Henry Bennahmias, the brand’s chief executive who led its North American operations at the time, recalled that the model was being sold at a discount. “We even thought at some point about stopping the model,” he said over Instagram, in a video discussion in late January with Austen Chu, the watch influencer known as @horoloupe. But the anniversary models helped put the 15202 “back on the map,” Mr. Bennahmias said during the discussion — the kind of boost that really isn’t needed now.

Still, to celebrate the Royal Oak’s 50th, 56 new references were introduced in January, from 34 millimeter to 41 millimeter, in three-hander, chronograph and tourbillon designs. Most feature a commemorative 22-karat gold oscillating weight engraved with a “50 years” logo and brand signature.

But the greatest changes are within, most notably a new Calibre 7121 that the brand said took five years to develop and that features a larger barrel for more power and precision and a patented extra-thin low-energy date-setting mechanism.

More anniversary models are to be introduced throughout the year — although the brand won’t disclose exactly how many — adding to the around 500 variations that have debuted over the years. But don’t expect any big party, as executives say pandemic regulations and travel rules have made it just too hard to plan. The decision also reflects a more subdued, mature approach to the model at 50.

“We don’t want to shout,” Mr. Bennahmias told @horoloupe about the anniversary. “It’s a lot more organic — less ‘We want to show who has the power.’ We are not in that mode.”