As thin as a knife and just as sharp, Jaeger-LeCoultre’s vintage-styled creation for The King’s Man movie is available in a limited edition of 100 and takes the cinematic wristwatch into the realm of high horological art.

Let’s imagine, for a moment, what kind of watch a sartorially snappy secret agent in the early days of WWI might have worn. Well, OK, you can bet it would have been of the pocket variety, since it was the war itself that predominantly influenced timekeeping’s move to the wrist.

Having said that, in the impeccably attired parallel universe of The King’s Man, the upcoming prequel to the Kingsman blockbuster series, who wouldn’t expect England’s dapper spooks to be significantly ahead of the game? And were one to distil the essence of Belle Epoque elegance, Savile Row sophistication, Swiss horological excellence and super-spy stealth into a single wristwatch, Jaeger-LeCoultre’s magisterial new offering – based on the slimmest and most elegant pocket watch of the pre-WWI era – is exactly where you would arrive. Conceived for a movie it may be, but thankfully this beauty is arriving on real wrists too, because this is as serious and sumptuous a piece of Le Sentier watchmaking as any.

To turn horological egghead for a moment, this watch is as exciting for what’s inside as out. Among Jaeger-LeCoultre’s myriad achievements over 187 years, its position as a pioneer in the field of slim watchmaking is not to be overlooked, though it hasn’t been so much to the fore in recent years. The Master Ultra Thin Knife brings back to the table Calibre 849, a movement so finessed that it takes the team in the brand’s Grand Complications studio – the guys who normally put together some of the most elaborate tourbillons and minute repeaters on Earth – to build it. With 123 components squeezed into an engine just 1.85mm thick and with an architecture that descends straight from the pocket watches of yore, this is true legacy watchmaking of the finest kind.

Speaking of pocket watches, the design itself comes from the model that really established Jaeger-LeCoultre’s credentials in the ultra thin category, an astonishing number from 1907 whose case, curving to a circumferential edge, gave it the nickname of “le couteau” (the knife).

The new watch picks up that design with a large bezel sloping to the edge of its rose-gold case, with the winding crown cleverly secreted at the pocket watch position of 12 o’clock, complete with vintage-style pointed bow to protect it. The entire watch is just a sniff over 4mm thick, meaning it’ll slide elegantly, and as stealthily as a spy, beneath the cuff of your Kingsman shirt.

Jaeger-LeCoultre Master Ultra Thin Kingsman Knife

Materials: Pink gold and alligator leather

Diameter: 40mm

Height: 4.25mm

Water-resistance: 30m

Power reserve: 35 hours

Price: £26,900