Reading about watches can often feel like cracking open a textbook. Browsing—and even buying—means being barraged with inscrutable words and phrases like ”tourbillons,” “perpetual calendars,” “minute repeaters,” and so on. So here, we'll be breaking down the meaning, history, and importance of different watch terms. Welcome to GQ's Watch Glossary.

In 1970, the world was groovy, and people were trading in classic mechanical watches for ones with light-up displays. Radical! Of course, things were less radical for Swiss watch brand Audemars Piguet, which was scrambling to figure out a counterpunch before the new quartz watches put it out of business. Executives threw a hail mary to Gerald Genta, a watch designer who was about to cement his status as a legend. An AP executive went to Genta with a brief one day at 4 p.m.: “Mr. Genta, I need a steel sports watch that has never been done before, I want it to be something totally new and waterproof,” he said, according to the designer. The subtext: come up with a watch that will save the company. Oh, and the design was due the next morning.

That night, drawing inspiration from deep-sea diving helmets, Genta sketched and designed the stop-sign-shaped Royal Oak. It turned Audemars Piguet into one of the most successful watch brands in the world.

Royal Oak

Released in 1972, the Royal Oak was the first stainless steel watch marketed as a luxury piece. It was a different era: in the early 1970s, when men still needed to wear watches to keep track of the time, they chose between stainless steel watches and dressy pieces built for black-tie soirees. The Royal Oak bridged those two worlds, creating a luxury watch out of the more durable steel. When it was first released, the AP was more expensive than Patek Philippe pieces made out of gold and 10 times the cost of many steel Rolexes.

People needed time to adjust to the idea of a new luxury-priced sport watch. It took three years for Audemars to sell 1,000 pieces—but, luckily, that first run went to the right people. Famously, the Shah of Iran was the first-ever Royal Oak customer. Audemars relied on powerful customers—influencers!—like the Shah to set the tone, and not long after that initial period of lackluster sales, interest shot way, way up. Now, the Royal Oak is Audemars’s flagship product.

Royal Oak

Audemars has benefited from the success of its tentpole product for decades. The Royal Oak now comes in versions encrusted in diamonds, built with tourbillons, and cooked up with perpetual calendars. And in 1993, Audemars introduced the Royal Oak Offshore, which beefed up the iconic design and came standard with a chronograph and the trio of pushers that complication required. (The watch’s designer Emmanuel Gueit later said that when the watch debuted at Baselworld, “Genta invaded the booth shouting that HIS Royal Oak had been completely destroyed.”) When earlier this year Audemars introduced an entirely new collection that went away from the Royal Oak, many of the pieces were met with skepticism by AP fanboys.

The Royal Oak and its offspring are also responsible for bringing new consumers into the world of watch collecting. In 2006, the brand’s then-American-president François-Henry Bennahmias let Jay Z take a crack at designing his own Royal Oak Offshore. In 2013, Bennahmias extended the same opportunity to LeBron James, who still frequently wears Audemars watches. It might not be a huge surprise to learn that Bennahmias is now the brand’s CEO.

But the watch’s most famous advocate just might be a fictional character: Ari Gold, the abrasive agent in Entourage, who received a Royal Oak from his boss on the show. Any watch that helped remind a guy when it was time to “hug it out, bitch” is clearly one for the history books.

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