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Audemars Piguet unveils the ultimate ultra-complication

Code 11.59 by Audemars Piguet Universelle, the ultimate ultra-complication

Many Swiss watchmakers have proposed watches that could claim the title of the most complicated wristwatch. Adding to the collection of its exceptional horological developments, Audemars Piguet builds on the savoir-faire from among its Grande Complication collection and proposes the crowning timepiece of complications - the Code 11.59 Universelle Ultra-Complication, also nicknamed RD#4. It features 23 complications, 40 functions, a new Calibre 1000, and is composed of 1,155 parts. The semi-Gregorian perpetual calendar of Calibre 1000 automatically skips leap year every 100 years. As a result, manual correction is required every 400 years. AP’s most complex wristwatch to date comes in a 42mm case size and four models.

Front views of Code 11.59 Universelle Ultra-Complication. All images © Courtesy of Audemars Piguet

More than a century after the production of its ultra-complicated Universelle pocket watch, Swiss Haute Horlogerie manufacturer Audemars Piguet introduces its very first ultra-complicated selfwinding wristwatch (RD#4) in the highly contemporary design of the Code 11.59 by Audemars Piguet collection. While paying tribute to the Manufacture’s legacy of high complications, the Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 has been crafted with ergonomics and contemporary usage in mind to offer unprecedented comfort and simplicity of use.

This pioneering mechanism builds on three generations of R&D innovations. Engineers, designers, watchmakers and craftspeople worked hand in hand for over 7 years to bring this RD#4 timepiece to life, continuously broadening their skills to push the limits of Haute Horlogerie craftsmanship to new heights. The Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 has been crafted with ergonomics and contemporary usage in mind to offer unprecedented comfort and simplicity of use.

“This new Ultra-Complication is the culmination of several decades of research, design and manufacturing of many different types of complicated mechanisms that have put ergonomics at the forefront of the process. To achieve the highest level of reliability, while also keeping the thickness of our calibres to the minimum, we believe that a ‘mechanical function with an ergonomic focus’ opens a new path for Audemars Piguet and the watch industry as a whole.” Giulio Papi Technical Director, Audemars Piguet Le Locle


The project debuted in 2016 with the goal of developing a highly complicated wristwatch fit for everyday use that would strike the right balance between complexity, ergonomics and aesthetics. Going beyond traditional norms of construction, the teams blurred the line between movement and case by developing ergonomic correctors and crown-pushers allowing users to activate the watch’s multiple functions with ease. They also incorporated and built on the Manufacture’s three recent R&D innovations – the Supersonnerie technology unveiled in 2015 (RD#1), the ultra-thin perpetual calendar movement launched in 2018 (RD#2) and the oscillator with increased amplitude premiered on the two Royal Oak Selfwinding Flying Tourbillon Extra-Thin RD#3 models released in 2022.

“The Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 is our quest to the Holy Grail with an incredible amount of savoir-faire fitted into a very small volume! We dreamt about it for 100 years, thought about it for 20 years and took seven years to bring it to life.” François-Henry Bennahmias, Chief Executive Officer, Audemars Piguet


The Manufacture’s uncompromising approach to craftsmanship and engineering guided the development of this ultra-complicated timepiece. The teams combined some of the most prestigious horological complications in one single selfwinding movement measuring no more than 34.3 mm in diameter (15 lignes) and 8.75 mm in thickness, while enhancing users’ comfort and experience.

The flyback chronograph can be started and stopped with the supercrown at 2 o’clock and reset with the other supercrown at 4 o'clock. The 4 o'clock crown also corrects the month in sync with the year. Among the innovations, the ergonomic crown-pusher – or “supercrown” – at 4 o’clock brings correction to a new level. While the pusher actuates the flyback chronograph’s zero resetting mechanism, the crown also enables the forward or backward correction of the month. In addition, the crown automatically returns to its neutral position after rotating it (up to 70°) in either direction. This ease of use hides highly technical mechanical devices located in both the crown and the movement, as well as a complex security system preventing misuse. Lastly, small intuitive symbols engraved on each crown and push-piece remind the wearer of their respective functions.

This watch was the ultimate challenge for our development team. It required an evolution of our internal processes in order to allow four people to work on the calibre at the same time. The level of miniaturisation achieved is a true milestone for Audemars Piguet and paves the way for the next generation of complicated mechanisms.” Lucas Raggi, Research and Development Director, Audemars Piguet


The Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 represents the latest in terms of chiming mechanism as it combines the sophisticated Grande Sonnerie with the patented Supersonnerie technology introduced by Audemars Piguet in 2015. A Grande Sonnerie timepiece strikes the hours and every quarter hour by passing (repeating the hour before the quarter every time), without any involvement from the wearer. In the Petite Sonnerie position, the watch chimes the hours only, while the automatic chiming is deactivated in the silent mode. Additionally, the wearer can activate the minute repeater mechanism at any time via the dedicated push-piece located at 10 o’clock. To optimise energy management and distribution, the timepiece’s chiming functions are fed by a dedicated barrel that is wound by the movement of the wrist, alternately with the main barrel.

This patented technology resulted from 8 years of research debuted in 2006 in collaboration with EPFL, the Swiss Federal Institute of Technology Lausanne. Inspired by the harmony of musical instruments, a dedicated community of watchmakers, technicians, academics and musicians reviewed the case construction to produce a patented chiming technology fit for contemporary, robust and water-resistant timepieces.

CODE 26398BC.OO.D002CR.02. The four 2023 timepieces are all fitted on a black alligator strap and come with an additional black textured rubber-coated calfskin strap for a touch of sporty elegance.

Three years of development were necessary to create a water-resistant sapphire component with the right geometry and thickness capable of acting as a soundboard. The “secret” cover features a series of apertures on the side to let air through and boost sound amplification when the watch sits on the wrist.


The semi-Gregorian perpetual calendar mechanism has been conceived to optimise the display and use of the calendar functions, while taking as little space as possible. To do so, Calibre 1000 builds on the patented innovations of Calibre 5133 premiered in 2018 with the release of the Royal Oak Selfwinding Perpetual Calendar Ultra-Thin RD#2 prototype, which merged the perpetual calendar 1 When the watch’s energy has run out, the two barrels can also be wound simultaneously thanks to the unidirectional winding of the crown at 3 o’clock. 5 functions onto one single level. The end-of-the-month cam has been similarly integrated to the date wheel, while the month cam has been combined to the month wheel. To enhance the watch’s ergonomics, additional calendar functions, such as the large date at 12 o’clock and the year indication at 4 o’clock, complement the perpetual calendar mechanism. Furthermore, the correction system of the calendar functions has been simplified for the user.

While the day and moon phases can be corrected thanks to two dedicated pushers located on the left side of the case, the reversible date system enables to move the date forwards and backwards by turning the crown at 3 o’clock in either direction. The month, too, can be adjusted forwards or backwards via the innovative “supercrown” at 4 o’clock. Similarly, the display of the perpetual calendar functions combines optimum legibility with refined aesthetics.

Calendar indications have been dissociated from the chronograph counters and organised symmetrically on the vertical axis. In addition to displaying the day, large date and month at 9, 12 and 3 o’clock respectively, the timepiece indicates the year thanks to a two-digit window located at 4 o’clock – a system which replaces the more traditional leap year indication. Synchronised with the month, the year changes automatically every time the month wheel moves from December to January. The semi-Gregorian perpetual calendar mechanism thus advances the day, date and year automatically taking into account the number of days per months, leap years included, as well as the 100-year correction normally required in traditional Gregorian perpetual calendars. No manual adjustment is therefore required before the year 2400!

CODE 26398BC.OO.D002CR.04

Lastly, the Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 incorporates an innovative instant-jump astronomical moon system that conveys a more realistic depiction of the moon. Two concentric discs, on which six different moon positions are printed, combine to form ten images faithfully representing the transitory waxing and waning stages between the New and Full Moon, as the satellite orbits around the Earth in an average of 29.53 days. As for other astronomical moons, this new moon image requires manual correction every 122 years, providing the watch has been kept fully wound. Located at 8 o’clock, its window display sits in perfect harmony with the year indication at 4 o’clock.


Audemars Piguet devised a contemporary split-seconds flyback chronograph interweaving simplicity of use with visual appeal. While the flyback chronograph allows to reset and restart the chronograph without having to stop it first, the split-seconds mechanism measures intermediate time intervals thanks to the addition of a split-seconds hand that can be stopped independently of the centre chronograph hand when the dedicated pusher is activated. When the push-piece is pressed again, it catches up to the running hand to continue their journey together around the dial, in perfect synchrony.

CODE 26398BC.OO.D002CR.01

CODE 26398BC.OO.D002CR.01

The action can be repeated at will. The flyback chronograph and split-seconds hand can be activated via the three crowns’ co-axial pushers on the case’s right side. The pusher at 2 o’clock starts and stops the chronograph, while the one at 3 o’clock actuates the split-seconds mechanism. Lastly, the pusher at 4 o’clock activates the flyback and zero resetting mechanisms. Most perpetual calendars follow the Gregorian calendar that skips the leap year when the century year is divisible by 100 but not by 400 to help synchronise the calendar year with the solar year. For that matter, traditional perpetual calendars will require manual correction in 2100, 2200 and 2300.

Contrastingly, the semi-Gregorian perpetual calendar of Calibre 1000 automatically skips leap year every 100 years. As a result, manual correction is required every 400 years instead of every 100. Furthermore, the Code 11.59 by Audemars Piguet Ultra-Complication Universelle RD#4 is equipped with a dedicated swivel clutch that prevents the chronograph centre hands from stuttering when the mechanism is started. This type of clutch was launched in 2015 on the Royal Oak Concept Laptimer. The architecture of the chronograph mechanism was further remodelled to save space and showcase components usually hidden from view on the caseback side. One of the major developments entailed integrating the split-seconds mechanism within the thickness of the central rotor’s ball bearing. By merging two systems usually superposed, Audemars Piguet engineers reduced the movement’s thickness by 1.1 mm, while revealing the beauty of the split-seconds mechanism when the user opens the watch’s “secret” cover. Lastly, to enhance the readability of the chronograph functions, the hour and minute counters have been enlarged and slightly decentred from the 3 – 9 o’clock axis to sit further away from the flying tourbillon cage at 6 o’clock.

To prevent the watch from stopping when all functions are working, the geometry of the escapement has been rethought to increase the amplitude of the balance and eliminate knocking – a state which occurs when excessive energy from the escapement is transferred to the oscillator. This solution also necessitated to increase the energy of the wristwatch’s base movement, while keeping a 21,600 vph frequency to highlight the beauty of the flying tourbillon on the dial side. A larger main barrel was thus developed to power the hands, as well as the chronograph and calendar functions, while the chiming complications are fed by a dedicated barrel. This more powerful mechanism grants the watch some 60 hours of autonomy when not on the wrist, depending if the functions are activated.

The timepiece also boasts for the first time a “secret” gold caseback that amplifies the watch’s acoustic performance when worn, and reveals the beauty of the mechanism thanks to the new Supersonnerie sapphire soundboard, once opened.

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