Play a simple word association game with anyone — say “watches” and the reply you get will most likely be “Rolex.”

The Rolex brand is so ingrained in the minds of much of the world, it’s hard to believe watches even existed before Austrian national Hans Wilsdorf started the company in the early 1900s.

It now stands as the most powerful watchmaker in the world, consistently ranking at the top of lists of the globe’s most reputable companies.

Rolex does not actually release sales numbers, but experts estimate that it makes roughly 1 million watches a year, presumably more than any other luxury watchmaker.

How did Rolex become this indisputable master of horology? According to Ben Clymer, the founder and executive editor of premiere watch enthusiast site Hodinkee, Rolex has built its brand on the back of incredible innovation, a name for rock-solid quality, and one of the most notable celebrity endorsements of the 20th century.

Basically: “Rolex is Rolex for a reason,” Clymer told us.

Innovation after innovation

A current Rolex movement. Rolex

Rolex’s status is no accident.

“Actual innovation in the watchmaking field is what propels Rolex to where they are now,” Clymer said.

To cement its status, Rolex invented: the first waterproof case, the first self-winding watch, the first watch with a date, and (arguably) one of the first driving chronographs.

Before watches became the luxury item they are known as today, they were tools, Clymer says. These innovations have made these watches much more usable.

A self-winding mechanism enables the wearer to avoid having to wind the watch every night, a waterproof case allows a diver to take the watch down with them and time their dives, and a driving chronograph allows race car drivers to time their laps with precision.

These innovations also make it easier to wear the watch every day. “You wouldn’t be able to wash your hands with a watch [without a waterproof case],” Clymer said.

A reputation for quality

On top of these innovations in watchmaking in the first half of the 1900s, Rolex developed a reputation for reliability.

In order for all of these innovations to function, and for the watches to operate as the tools they were intended to be, the watches had to be the best. It’s important to remember that these were not simply luxury items as they are viewed today, Clymer says.

“If you were a navy diver and you wanted something that would simply last forever and was a tool, and would survive going to 100 meters, [you bought a Rolex],” Clymer said. “Because it just works.”

Swimmer tested, swimmer approved

British swimmer and first Rolex Brand Ambassador Mercedes Gleitze. AP

Innovation and quality is great — but it does you no good unless potential customers are aware of it.

In 1927, Wilsdorf approached Mercedes Gleitze, the first woman to swim the English Channel (and the first person to swim the Strait of Gibraltar), and asked her to wear the new Rolex Oyster watch, complete with waterproof case.

The swimmer agreed and wore it around her neck during an attempt to swim the channel.

“This woman, who was then being photographed on the front page of the newspaper every day, was wearing a Rolex around her neck,” Clymer said.

Though she didn’t actually complete the swim on that attempt, Gleitze’s celebrity status catapulted Rolex’s name into the public consciousness, and Rolex was able to talk up the fact that the watch kept time even after being submerged in cold water for hours. This greatly increased brand awareness and the public’s opinion of Rolex’s quality.

Rolex has since used images of women swimming while wearing their watches in its advertising, even as recently as 2010.