L.Leroy OSMIOR “BAL DU TEMPS”

L.Leroy celebrates its 240th birthday this year, marking an important new chapter in its illustrious history.  The Geneva Watch Days event will see the world premiere of a stunning new creation, representing the brand’s return to the forefront of Haute Horlogerie: the L.LEROY OSMIOR “BAL DU TEMPS”.

Timepieces crafted by L.Leroy, the esteemed Maison that was established in Paris in 1785 by Charles Leroy, have spanned the centuries, bestowing their distinguished owners with unparalleled elegance and distinction. In 2025, the year of its 240th anniversary, L. Leroy is proud to continue to fascinate and mark the time of enthusiasts and discerning connoisseurs of fine mechanical watchmaking with a new and exceptional work of art equipped with prestigious complications.

This latest novelty marks a new milestone in the perpetuation and evolution of the brand. Named BAL DU TEMPS, it is part of the Osmior collection, characterised by classic aesthetic codes.   It is a model that features complications of the highest technical level, such as the Tourbillon and the Minute Repeater, which will be produced in limited quantities and manufactured exclusively for L. Leroy in Geneva. This extraordinary masterpiece of fine craftsmanship and mechanical engineering will make its world premiere at the Geneva Watch Days event, where it will be on show at the Hotel Beau Rivage from 4 to 7 September 2025.

This new creation, available in three variants, marks the beginning of a new era for L.Leroy, whose desire is to keep its glorious past alive while fully respecting the brand’s DNA.  Great attention is therefore paid to the aesthetic canons that define it, the exquisite finishes that enhance its fascinating beauty and the intricate mechanics with their impressive complications.

A refined and unmistakable aesthetics: The case: sinuous lines define its classic allure

The case is crafted from noble metals such as 18K 5N red gold and platinum, as well as a more modern material, grade 5 titanium, which is highly appreciated for its lightness. These three variants have a diameter of 43 mm and a height of 13.60 mm (including the domed sapphire crystal), which is a moderate thickness considering the movement’s complications.

With a polished surface and a “tambour” shape, a signature feature that immediately identifies the Osmior collection, it is distinguished by its flat, recessed case middle in relation to the bezel and the case back. The lugs are chamfered and slightly flared, with rounded ends. The crown is engraved with the polished, interlaced double ‘L’ of the Maison’s logo, which stands out against the sandblasted surface. Grooved notches around the circumference facilitate the grip when winding the watch and setting the time. 

But the meticulous attention to detail does not stop here.

Various measures have also been taken with regard to the ring that secures the sapphire antireflective crystal to the rear of the watch. While the outer perimeter is flat, the inward-facing part has domed segments, interrupted by the positioning of the six fixing screws. These portions have been created using the embossing method. Bordered by a polished profile and a sandblasted surface, they display polished relief engravings that define the watch’s identity.

The case of the BAL DU TEMPS is water-resistant up to 3 atm and a black alligator strap with large scales and tone-on-tone stitching secures it to the wrist. The inner lining is also made of alligator leather, but with small scales. The exclusive design for the folding buckle, in materials matching the case, consists of the double “L” logo which is positioned inside a ring, thereby giving it an original style. 

The Dial: a delight for the eyes

The dial becomes the stage on which the play is performed.  The title of the play is BAL DU TEMPS, written and directed by L. Leroy. This sophisticated piece pays homage to its historical heritage and the tradition of Swiss high-end watchmaking, with every detail accurately designed to meet the highest standards of this art.

The openworked dial is a veritable hymn to micro-mechanics, showcasing the intricate mechanics equipped with the prestigious Minute Repeater and Flying Tourbillon devices, the latter visible at 6 o’clock. Only highly qualified watchmakers can design and assemble these two complications to perfection, resulting in perfectly harmonious sounds and excellent chronometric precision.

In addition, an intriguing detail immediately demands attention: the display features a single hand, that of the hour, while the minutes are indicated by an exquisite acoustic mechanism, known as the Minute Repeater, which is activated by a slide located at 9 o’clock. A time reading that is not totally new for the Maison, which is inspired by the historic “a tact” watch made for Prince Emil Maximilian Leopold August of Hesse around 1810 and which has already been the subject of a recent timepiece produced by the brand.

L.Leroy is keeping this “fil rouge” alive!

The sunray-finished hour ring features Arabic numerals reminiscent of L. Leroy’s historical pieces.  Each case material adopts a different colour, endowing each watch in the collection with its own unique identity. The palette ranges from silver on the titanium, providing a very discreet tone-on-tone effect, enlivened by the ALD-treated blue hand; light ALD-treated blue combined with precious platinum and a rhodium-plated hand; and anthracite grey, against which the gilded numerals and hour hand stand out on the 18K5N case version.

At the centre of the dial, levers and gears move in perfect harmony to fulfil the mission for which they are intended. These components have been refined to perfection. A number of these elements are satin-finished, while others are polished. The plate is embellished with circular graining, and the screw heads are polished. 

Superbly crafted, the flying tourbillon cage at the 6 o’clock position completes a full rotation in one minute and is adorned with a bridge bearing the interlaced double “L”, the House’s symbol. Made of shiny titanium, it has bevelled and polished profiles and is fixed by white gold screws and pillars.

The combination of the many elements gives dynamism, depth, and a personality all its own to this masterpiece of time, which is offered in three variants. They showcase the exceptional expertise of the watchmakers and artisans while preserving the brand’s heritage with an eye to the avant-garde spirit of the 21st century.

A valuable mechanics with great complications

At the heart of the new BAL DU TEMPS lies the L601SQ calibre, featuring two of the most noble watchmaking complications: the Minute Repeater and the Tourbillon, which is a flying one in our model.

The complications and some historical notes

The earliest examples of the minute repeater — a sophisticated and complex mechanism representing the pinnacle of watchmaking artistry, earning it the nickname “the queen of complications” — date back to the 17th century. During this period, two Englishmen, the Reverend Edward Barlow and the watchmaker Daniel Quare, laid the foundations of this invention, adopting slightly different approaches.  The purpose of the minute repeater device was to convert time into sound on demand, which was necessary due to the difficulty of reading the dial in the dark before the advent of electricity.

In 1783, the French watchmaker Abraham-Louis Breguet perfected this invention by replacing the initial bells with gongs. Initially rectilinear in shape and placed on the back plate, these springs later became circular and positioned around the movement. An ingenious system that made it possible to reduce the thickness of the movement.   There are usually two gongs, struck by as many hammers that acoustically strike the hours, quarters and minutes in different tones.