Founded in 1865 in Le Locle by Georges Favre-Jacot, Zenith quickly earned a reputation as the manufacturer of some of the most precise timepieces of those years achieving the first prize in the chronometry competition of the observatory of Neuchâtel in 1903. Over the years, Zenith won many more competitions achieving the impressive record of more than 2,300 prizes considering pocket watches, on board instruments and wristwatches
These successes accelerated the growth of the company which was transformed into a stock company in 1911. After the First World War Zenith began with the development and manufacture of wristwatches, including alarm and chronograph functions.
While automatic movements for “solo-tempo” or three-hand watches started becoming popular in the 1940s and 1950s, no automatic chronograph movements had been manufactured yet.
In 1962, Zenith began developing the idea of creating the first automatic chronograph in watchmaking history with the ambition to launch it in 1965, on occasion of the centenary of the Manufactury.
Instead of considering the easier option to add a chronograph module to a base movement, Zenith had a more ambitious plan: the chronograph function had to be fully integrated within the mechanism and actuated by a column wheel rather than by an easier-to-implement cam. And to make things even more challenging, the beating frequency of the chronograph had to be high enough to make it the most accurate chronograph wristwatch in the world measuring 1/10th of a second. A relatively small size and a date indication were additional specifications.
With all these requirements, the bar was raised so high that the project could not be completed in time for the centenary in 1965 but it required four more years.
In 1969, at a press conference held on January the 10th, Zenith announced the imminent launch of the first fully integrated, high-frequency, automatic chronograph movement. Codenamed 3019 PHC, this movement was renamed “El Primero”, which means “the first” in Spanish.
The El Primero 3019 PHC, here shown without its winding rotor
Excerpt from a service manual of the El Primero 3019 PHC
Despite the announcement, the Zenith El Primero debuted later in the year, in September, thus making it possible for other competitors to start selling their automatic movements a few months in advance.
In fact, Seiko and the Chronomatic Group (a partnership between Heuer-Léonidas, Breitling, Hamilton-Büren and Dubois-Dépraz) were also running the race to the first automatic chronograph movement. Seiko had quietly introduced their own 6139 automatic chronograph movement to the Japanese market only in May while the Chronomatic Group released its first example in August.
We think it is not particularly important to determine who actually arrived first in the race. Working prototypes of all three movements were available at the same time. It must instead be remarked that the three movements had significant differences.
The Zenith El Primero had special features that set it apart. The 1969 advertisement below well emphasized its peculiarities.
Zenith El Primero advertisement from the Swiss Watch and Jewelry Journal (issue of March 1969)
Zenith and Movado (at the time the two brands were owned by the same holding) explained these features in their announcement: “The Zenith and Movado watch companies have achieved an extraordinary feat in combining two precision watches in one. It comprises a high-frequency automatic watch with calendar along with a timer-chronograph allowing time measurements to the tenth of a second. It is equipped with an hour and minute timer. This is the first watch of its type in the world. The extraordinary feature is that both these mechanisms fit in a space smaller than that of a traditional chronograph. This model has all the advantages of a standard watch plus the date, automatic winding and the chronograph with timers and calendar.”
The first El Primero timepiece that appeared in a Zenith advertisement (March 1969) was the A384 reference.
Above and below, Zenith El Primero A384, 1969
Nonetheless, the lowest production serial numbers can be found on the casebacks of the A386 which led Zenith to consider the A386 the very first El Primero Chronograph manufactured in 1969 while the A384 remains the first model to be presented in advertisements.
The El Primero A386 with its typical subsidiary dials in blue, light grey and anthracite, 1969 - Courtesy of Phillips Watches
The two references had several differences. The A384 had an angular tonneau stainless steel case with a diameter of 37 mm and a silver dial with with black subdials and tachymeter scale.
The A386 had a more traditional round case with a thin bezel allowing the dial to have more space thus improving readability. Together with the tachymeter scale, it featured a decimal dial ring dividing a minute in 100 units. The big subdials, overlapping each other, had three different colors, a detail which will become a signature of the El Primero chronographs.
The A385 is a less know reference. Two dials were used for this model, with different shades of khaki and with silver or white subdials. Other shades that can be seen in the vintage market are due to the aging of the dial.
El Primero A385, circa 1971 - Courtesy of Christie's
Unfortunately, despite all the excitement for this important innovation in watchmaking, the quartz crisis was at the door. In the late 1960s/early 1970s, the invasion of Japanese quartz watches posed a serious threat to the Swiss watchmaking industry.
In 1970, 16 Swiss brands, including Zenith, created a consortium for the creation of watches equipped with a Swiss-made quartz movement (the famous Beta 21). Zenith was part of the adventure. The Swiss were quickly joined by the Americans – Motorola, Texas Instruments, and National Semiconductor - but none caught up with the Japanese Seiko and Citizen.
Within such a context, in 1971 the company was sold to Zenith Radio Corporation, originally a radio and then television manufacturer based in Chicago. The holding company MZM (Mondia Zenith Movado) was dissolved and in 1972 the brand continued as Zenith Time SA managed by USA administrators. During this period, the El Primero movement still appeared in the manufacturer's catalogues but without being a sales hit.
In 1971, with the reference number AH 781, the El Primero movement was housed in a case that can be considered a precursor of the modern Defy model. The dial was characterised by the three partially overlapping counters.
El Primero AH 781, 1971
The "Espada", the "TV" (with blue or black dial), the "C-case" (in steel or goldplated), and the "Movado Zenith" were other remarkable models that remained in production till 1975. In these models, a new Zenith logo is used on the dial.
El Primero Espada, circa 1972 - Courtesy of Phillips Watches
But the US management had lost confidence in the future of mechanical watchmaking betting on the success of quartz and, that year, they decided to stop the production of mechanical movements. It is estimated that around 32,000 El Primero, in 18 different models, were produced in the 1969-1975 timeframe (18,000 in 1969-1972 and 14,000 in the following three years). Of these, only 2,500 examples of the A386 were produced, making this reference very rare and highly prized by collectors.
In 1976, the management resolved that the metal of the presses and the tools required to manufacture the movement had to be sold by the ton to the highest bidder.
Luckily, Charles Vermot, the Zenith watchmaker in charge of the Workshop 4 where every El Primero chronograph movement was assembled after no less than 2,500 operations, disagreed with this decision still believing that mechanical watchmaking had a future. In order to convince the US management to change their mind he explained his vision: "Without being against progress, I note that the world often goes through various cycles. You are wrong to believe that the automatic mechanical chronograph will die out completely. I am thus convinced that your company will one day benefit from the whims and fashions that the world has always known."
Charles Vermot in the early 1970s
He then asked for permission to keep all the tools necessary for the manufacture of the El Primero movement in a small dedicated workshop but his request remained unanswered.
Well aware of the great value of those tools and the related unique know-how, Charles was ready to take the risk to lose his job. With the help of his brother Maurice, also a Zenith employee with responsibility for the manufacturing of the presses, he hid all the presses, cams, operating plans, cutting tools and manufacturing plans necessary for the creation of the El Primero movement in one of the 18 buildings of Manufacture Zenith. He chose the more isolated store on the top floor. Since he was violating hierarchical orders, he had to act at night passing the heavy equipment through a passage at the back of the building and climbing 52 steps! Security was not an issue because, as a workshop manager, Charles had all the keys. He then hid everything behind a wall.
In all, Vermot managed to save about 150 presses along with many small tools and cams, an equipment worth several millions Swiss francs at present values. Without these presses, it would have been impossible to produce El Primero again as they were part of the trade secrets.
By 1976, Zenith had lost most of its staff producing watches powered by ETA or Citizen quartz movements. The rare mechanical movements in use were also sourced from ETA.
The company was not profitable so, in 1978, Zenith Radio Corporation sold Zenith Watches SA to a consortium of three Swiss manufacturers, including Paul Castella, a Le Locle entrepreneur very much focused on preserving jobs in his region that wanted to preserve the Swiss industrial and watchmaking heritage represented by Zenith.
By the early 1980s the demand for mechanical watches started to grow again. The improved scenario helped Zenith to recover from the years of crisis. The company also started to supply some of its movements to other brands.
The old El Primero calibers in stock since the early 1970s were bought by the Ebel brand which wanted to have an automatic chronograph with an exemplary movement to offer in his 1981 catalogue.
The opportunity to restart the production of the El Primero arose when Rolex decided to update its Daytona with an automatic chronograph movement. The El Primero appeared to be the best technical option in this category and, moreover, its counter configuration (at 3, 6 and 9 o'clock) was just ideal for the Daytona.
The 5 Hz (36,000 vph) frequency was not an issue because it was possible to reduce it to 4 Hz (28,800 vph), more customary for Rolex watches.
But Rolex needed large quantities of the El Primero. Thanks to the bold and resolute move of Charles Vermot, Zenith was still in the position to take the commitment and in 1984 production of the El Primero calibre could begin once more.
Charles Vermot in the late 1980s
What Vermot had predicted, came true. He had labelled all the presses and all the tools, he had kept and filed all the dossiers and instructions useful for its restart. The filing and archiving work that he carried out enabled Zenith to be operational quickly enough to restart production.
A ten-year contract was signed with Rolex. The first movements were delivered in 1988 and the first Daytona watches equipped with a Zenith movement were presented at the Basel Fair that same year (the reference 16500 series).
Following this important contract, it was time for the Manufacture to relaunch production and equip its own models and chronographs with its own in-house calibre.
This began with new chronograph models to support the company's flagship lines: Academy and Cosmopolitan. For the first time, the Manufacture revealed through the back of its models the calibre that was its pride and joy.
Then came a line entirely dedicated to chronographs: the De Luca line, launched in 1988. Its models were inspired by the successful aesthetic codes of the time, somehow evoking the design of the Daytona, of which the first models equipped with the El Primero had just been released in Basel.
El Primero De Luca, circa 1990 - Courtesy of Sotheby's
The first appearances of the El Primero through a sapphire case-back happened in the 1990s with the top-of-the-range ChronoMaster line, which displayed its flagship movement through the transparent back.
Above and below, the ChronoMaster El Primero ref. 30-0240-410, 1994
Two years later the El Primero was equipped with the new Flyback function specially dedicated to aviation enthusiasts and enriching the Rainbow Flyback models launched in 1997.
In the 1990s mechanical watchmaking experienced a renewed interest from a growing public of enthusiasts awakening the attention of luxury groups which started buying brands with high added value.
With its glorious history and a production facility capable of creating its own movements, Zenith represented an ideal target. In 1999 the luxury giant LVMH (Moët Hennessy Louis Vuitton) bought the company, with the takeover coming into full effect in 2001.
Under the LVMH group, the Zenith brand was positioned even higher as demonstrated by the integration of sophisticated horological feats: in 2004, the movement adopted a tourbillon for a model named Grande ChronoMaster XXT Tourbillon El Primero, resulting from three and a half years of research and development. This was the first high-frequency tourbillon on the market.
Reference 65-1260-4005, the first El Primero Chronograph integrating a tourbillon, circa 2004 - Courtesy of Sotheby's
This model was followed by a perpetual calendar, the Grande ChronoMaster XXT Perpetual Calendar, and in 2005 by a minute repeater, the Class Traveler, an exercise that required the filing of 30 patents. Finally, in 2007, Zenith combined the tourbillon and the perpetual calendar within the same timepiece belonging to the Academy line.
In 2003, the ChronoMaster Open confirmed the "star" status of the El Primero movement making the 36,000 vph beating heart of the movement visible through a dial opening. Several variations followed, including feminine versions.
ChronoMaster El Primero Open, circa 2004
A breakthrough came in 2010 with the launch of the El Primero Striking 10th featuring the first automatic movement capable of measuring and displaying tenths of a second.
The original El Primero calibre introduced in 1969 had a cadence of 10 vibrations per second while other calibers were generally reaching a maximum of 8 vibrations per second.
The rose gold version of the El Primero Striking 10th, 2010
The El Primero Striking 10th rendered each pulsation of its motor clearly visible. Directly connected to the regulating organ, each jump of the central chronograph hand marked a 1/10th of a second, the smallest division of time measured by a series-produced mechanical calibre at the time. In this model the chronograph hand makes a complete dial rotation in 10 seconds and each of its steps precisely indicates a 1/10th of a second against the 100 graduations engraved on the dial.
In a continuous quest for extreme precision, Zenith did not consider this impressive achievement a limit. In fact, in 2017, the Swiss brand launched the Defy El Primero 21, which was able to measure and display a mechanical value that was difficult to imagine: one hundredth of a second.
This was made possible by an 'engine' oscillating at 50 Hz, ten times faster than its legendary predecessor, with the heart of the movement beating at a dazzling speed of 360,000 vibrations per hour and the central chronograph hand making a complete turn of the dial in one second. You can read more about this breakthrough in our presentation article.
The Zenith Defy El Primero 21 with silver-toned dial and black counters (on the left) and with an openworked dial, 2017
2019 marked the 50th anniversary of the El Primero. Together with its technical evolution, even the basic movement has been reworked and improved to facilitate its assembly. It naturally maintains all its aesthetic and technical characteristics: it is still an integrated high-frequency movement, the date indication is kept, as are the lateral clutch and column wheel. It comprises a few less components than the original model and the Manufacture has added certain elements it deemed important, notably including the stop-seconds device and a greater power reserve.
Zenith celebrated the event in January 2019 with the release of the 50 Years of El Primero Anniversary Set, a boxed set containing three chronographs, all characterized by the typical tricolor counters (light grey for seconds, blue for minutes and anthracite for hours): a faithful reissue of the first El Primero model of 1969; a Chronomaster El Primero with optimized movement; and a Defy El Primero 21 to 1/100th of a second.
Few months later, on occasion of Baselworld 2019, it was the time of three El Primero A386 Revival models in white, rose or yellow gold faithfully reproducing the characteristics of the 1969 El Primero: a 38 mm diameter case, a domed crystal, three-colored counters, a tachymeter scale, as well as the shape of the hands and hour-markers. The mushroom-type pushers and lugs are also identical to the original, thanks to the "reverse engineering" process adopted. Issued in 50-piece limited editions, these models came with with a 50-year guarantee.
The El Primero A386 Revival
In 2021, with the release of the Chronomaster Original, Zenith brought back the design of the A386 in a non-limited steel version empowered by the latest version of the El Primero calibre, dubbed the El Primero 3600, offering 1/10th of a second precision and time measurement. You can read our full review here.
In 2024, Zenith expanded its high-frequency chronograph offerings with the Chronomaster Original Triple Calendar, incorporating triple calendar and moonphase complications into its signature design.
Symmetrically placed windows above the chronograph counters display the day of the week and month, while the date window is positioned at 4:30. A moonphase display elegantly complements the 60-minute chronograph counter at 6 o’clock.
One standout variation features an opaline slate-grey dial with silvery-white counters and scale, a design inspired by a rare 1970 prototype of the El Primero with triple calendar functionality.
By Alessandro Mazzardo.
First published on August 6, 2019. Latest revision on December 1, 2024.
© Time and Watches. All Rights Reserved. Copying this material for use on other web sites or other digital and printed support without the written permission of Time and Watches or the copyright holder is illegal.
- Read about other iconic watches.First published on August 6, 2019. Latest revision on December 1, 2024.
© Time and Watches. All Rights Reserved. Copying this material for use on other web sites or other digital and printed support without the written permission of Time and Watches or the copyright holder is illegal.
