"Cartier invented the wristwatch," Mr Pierre Raniero, the company's director of image, style and heritage, declared as he sat down in his office in a surprisingly nondescript building in central Paris.
However, few things are entirely clear in the watch world: Breguet, Patek Philippe and Girard-Perregaux all say they produced timepieces for the wrist before French watchmaker Louis Cartier made one for an aviator friend in 1904.
According to Mr Raniero, the house also pioneered turning the functional item into a gloriously stylish one by adorning its wristwatches with gemstones.
Other claimants, get in line.
Regardless of which house was first, a dazzling effect was produced. As brands have sharpened their focus on women buyers in recent years, the category continues to expand.
"Women like a little bling on their watches," said Ms Sue Perry, the content director at David Perry & Associates, the New York-based publisher of custom magazines for jewellery and watch retailers.
"Even sporty watches, such as Tag Heuer's Aquaracer and Rolex's Yacht-Master 40, mix diamonds and gemstones with no-nonsense features such as rubber and tough fabric straps," she said. "And it's a trend that crosses all price points.
"One of the reasons behind this is that diamonds - in more discreet doses - have become an everyday look."
She added: "We're seeing a fashion throwback - the gem-encrusted bracelet watch - making a return. This is not for everyone's lifestyle, but there is a consumer who wants that extra razzle-dazzle in a special-occasion timepiece such as Bulgari's Serpenti, which is really coming on strong."
But should a prospective buyer first consider the watch or the embellishment? After all, at its heart, the creation process is either jewellery companies adding movements to their jewellery or watch companies adding gemstones to their watches.
Mr Laurence Graff has made his name buying some of the world's biggest and best diamonds, the kind that have their own names - such as the 1,109-carat Lesedi La Rona, the largest rough diamond in existence, which he bought in September.
His company has become the place for a woman who wants a diamond ring that tells time, or a diamond bracelet watch with a huge slice of emerald covering its dial, or a watch hidden under diamond-covered butterfly wings that fan open to reveal the face, designed to complement her butterfly earrings.
Mr Graff's son, Francois, the company's chief executive officer, said: "Despite the concept of secret watches being age-old, dating back to the 1920s, we are receiving more requests for jewels with hidden timepieces as well as cocktail watches featuring innovative diamond-setting techniques and technical movements."
The house's design director, Ms Anne-Eva Geffroy, sitting at her drawing table in the company's Mayfair townhouse in London, said Graff's focus on beautiful gems "allows us to give our own touch to watches using these exceptional stones. It starts with the stone and what the stone suggests."
Snowfall, created by the house's design team, is a collection of necklaces, bracelets and earrings made of mesh sprinkled with diamonds to resemble a dusting of snowflakes.
The designers wanted to add a watch to a bracelet, but needed a very thin movement. So, they had the Swiss company that produces Graff's movements make a 5mm-deep unit that could slide unobtrusively into the design.
In contrast, the watch is the starting point at Vacheron Constantin.
"We make all our own movements," said Ms Leslie Kobrin, the brand's president of the Americas, who came to the watchmaker after serving as vice-president of business development at a fellow Richemont company, Van Cleef & Arpels.
Her view is that a jewelled watch should come from a watch company.
She said: "Many houses have access to beautiful stones, but they have to go out-of-house for their movements."
Sure, Vacheron Constantin can simply "add a diamond on a bezel", she said, practically sniffing.
But its artisans can also create the Ottoman Architecture watch from the brand's Metiers d'Arts Fabuleux Ornements Collection, engraving and chamfering a gold disc to create a delicate, lace-like piece that is then set with half pearls, worthy of Ali Baba's cave.
As for the future, Ms Kobrin said: "What I see evolving is the segment of jewelled watches with serious mechanical movements inside", as well as "high-low fashion trends reflected in watches, such as a multi-carat diamond watch made in steel, with an automatic calibre. Women want watches they can wear and enjoy every day".
In Cartier's offices, Mr Raniero pulls out illustrations showing how jewelled watches have reflected the times.
As early as the 1700s, women wore timepieces disguised as pendants or dangling from a belt.
The early 1900s saw lots of colourful watches, inspired by the Ballets Russes and its 1910 production of Nikolai Rimsky-Korsakov's Scheherazade.
After World War I, "black was very big as women were in mourning", he said.
And in the 1930s and 1940s, gold became important.
"It's something we're seeing again today," he said.
So, which to buy, a jewelled watch from a jeweller or one from a watchmaker?
It all depends on who you ask.