A piece unique watch is both thrilling and frustrating. The rarity and – often – exotic character of a singular standout appeals to a watch collector’s longing for exclusivity and excellence. But only one fortunate soul can enjoy the pleasure of its company.

Your author wearing the De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

The De Bethune DB17 Piece Unique is a technical tour-de-force by two of the greatest minds in modern watchmaking, and it embodies a thrilling combination of beauty and ambition.

Herein, I offer an illustrated survey of something all humanity but an elect of one will never call “mine.”

I’d be remiss if I were to elide the fact that the company I work for, The 1916 Company, owns De Bethune. You’d be forgiven for thinking that this article is a sales pitch, but you’d be wrong. This watch is sold, gone – off the table.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece on the wrist

As a piece unique for nineteen years with a base movement from the now defunct Christophe Claret, this DB17 can be pronounced the first and last of its kind. Better luck next time.

The story of the DB17 begins in 2004 when De Bethune co-founders Denis Flageollet and David Zanetta launched the DB15 perpetual calendar.

De Bethune DB15 RT (photo courtesy Christies)

While the initial De Bethune models from 2002-2004 employed calibers sourced elsewhere, the DB15 ensconced a twin-barrel manual winding manufacture caliber “DB2004” with five days of power reserve and Flageollet’s original perpetual calendar module.

De Bethune DB1 Chronograph

The design language was still that of the first DB1 chronograph: solid dial, round case, fixed lugs. With 98 examples produced, the DB15 was something of a best-seller by early De Bethune standards.

Flageollet loves to experiment, so a DB17 perpetual calendar arrived in 2005 with detail tweaks to the DB15. A thicker bezel added visual weight; the dial’s hour and minute tracks were slimmed to compensate.

De Bethune DB17 from 2005 (photo courtesy Ineichen.com

Roman numerals remained, but the leaf hands of the DB15 were replaced by a modified Breguet style.

Finally, the radial rosette guilloché of the DB15’s dial gave way to a soleil burst with an origin point beneath the moonphase at 12 o’clock; a “sunray” motif beneath a moonphase may have been Flageollet’s subtle expression of irony.

26 examples of the DB17 were sold. At the De Bethune of 2005, the DB15 and DB17 series were considered to have been sales successes. But there was one more evolution of the family to follow – an evolutionary dead end as exquisite as it was conclusive. That is the watch featured here: the DB17 Piece Unique.

2004 was boom time for absurdly complicated watches. Greubel Forsey roared into the public’s imagination with a twin-tourbillon statement of intent; F.P. Journe won the GPHG Aiguille d’Or with his remontoir-metered Tourbillon Souverain and its 18-karat rose gold movement.

Christophe Claret, long a low-key white label constructor for the elite, emerged from behind the curtain with the Harry Winston Opus 4 under his own name. Its double-sided display, calendar, moonphase, and tourbillon were merely opening acts for Claret’s traditional main event: a minute repeater.

Harry Winston Opus 4 by Christophe Claret

Twenty examples were made before – his honor satisfied – Claret returned to contact work for another five years before launching his eponymous brand in 2009.

Actually… make that 20.5 examples. One of the Opus 4 calibers found its way to L’Auberson, the home of De Bethune. In 2005, Flageollet undertook an epic-scale rebuild of the Claret caliber with a milestone-level unique model in mind.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Out went Claret’s double-dial setup, moonphase, and pointer calendar. In came the De Bethune DB17 perpetual calendar and its patented spherical moonphase display. With two hemispheres composed of blued steel and white palladium, the DB phase de lune remains true for 122 years between settings.

Back of the De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Flageollet implemented his latest patented balance design, a tri-spoke titanium spinner with teardrop-tapered platinum masses. A hand engraved “De Bethune” signature on the barrel bridge leaves no doubt as to the adoptive father of this particular Claret ebauche.

Exquisite details abound. Start with the regulator itself. The balance wheel features a classically beautiful overcoil hairspring rather than Flageollet’s usual double-curved flat profile. There’s a hand-engraved golden scale for the regulating index of the balance.

Movement of the De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece: minute repeater regulator at 5 o’clock, balance assembly at 2 o’clock

A mirror-polished and beveled steel tourbillon cage leaves no surface raw, and there’s a tourbillon bridge with flanking mirrored and rounded steel beams.

Balance timing regulator scale (bottom left) of the De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Concave anglage profiles – one of the industry’s rarest feats – envelope each end of the tourbillon bridge.

Repeater features are world-class. First, the strike governor is so small as to be nearly invisible; it sits under a small cock between the barrel bridge and the repeater striker. The tiny gold mass spins in absolute silence – the better to leave “cathedral” gong chimes unsullied by background racket.

Unlike a conventional repeater gong, the cathedral variety encircles the movement 1.5 times rather than once to produce a richer sound.

Claret’s use of “Sandwick” tempered steel from Sweden sweetens the tone of the strikes, and volume is excellent. There’s no perceptible deadening of the repeater despite this watch’s massive rose gold case.

Broad hand polished polished bevels of the De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Additional highlights revolve around the quality of the decoration. Broad hand polished polished bevels remind the viewer how far even modern Holy Trinity anglage has been automated for the sake of volume. Stripes are deep, sharply grooved, and luminous.

Repeater strikers are as black as poli noir gets and beveled to points sharp enough to injure a careless watchmaker. Jewels and screws sit in mirror-polished recesses.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Externally, this DB17 departs only marginally from the series-production model – if we can characterize the 26-piece DB17 as “series” production.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece side on

Major changes include a thicker case, a unique arrangement of dimple-type pusher adjusters for setting the calendar, and a freehand engraved caseback.

The latter includes careful burin-cut characters for the brand name “De Bethune” and the “Pièce Unique” notation.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

Since its earliest days in the 2000s, De Bethune has provided and continues to provide custom editions for clients with unique visions and budgets to match.

While most of these amount to aesthetic variations on core models, an occasional piece unique spirals beyond mere appearance into the realm of bespoke watchmaking and engineering.

De Bethune DB17 Minute Repeater Perpetual Calendar Unique Piece

The DB17 Piece Unique illustrates the scope of possibility at De Bethune when limitless imagination meets a limitless budget. Either that, or Denis Flageollet was just showing off. Both are to be encouraged.

For more information, please visit www.debethune.ch/en/collections/heritage/heritage-list/heriage-2005/db17

Quick Facts: De Bethune DB17 Piece Unique
Edition: 2005, 1 piece
Functions: Perpetual calendar, moonphase, minute repeater, tourbillon
Case: Rose gold; 43.4mm diameter; 15.2mm thick; 49.1 lug-to-lug; 22mm lug spacing; flanking push pieces for calendar, 0 meters of water resistance
Dial: Hours, minutes, spherical moonphase, perpetual calendar with day, date, month, and leap year indication
Movement: Caliber Christophe Claret Opus 4 base; manual 53-hour power reserve; 2.5Hz; overcoil hairspring; proprietary titanium and platinum non-annular De Bethune balance wheel; minute repeater with silent governor and cathedral gongs, De Bethune perpetual calendar, 5x adjustment
Strap: Blue double-sided alligator leather strap
Clasp: Rose gold pin buckle
2024 Preowned Price : $500,000

* Tim Mosso is the media director and watch specialist at The 1916 Company. You can check out their very comprehensive YouTube channel at www.youtube.com/@the1916company.

You might also enjoy:

De Bethune DB Eight: The Ultimate in Chronograph Refinement!

De Bethune DB28GS Yellow Submarine Reviewed by Tim Mosso

De Bethune DB Kind of Two Jumping GMT Reviewed by Tim Mosso

De Bethune DB25 Midnight Blue Reviewed by Tim Mosso