The Chronomatic was one of the first automatic chronograph movements. Developed by a consortium including Heuer, Dubois Dépraz, Hamilton-Buren, and Breitling, the movement was also sold as the calibre 11, calibre 12, calibre 14, and calibre 15.

One immediately noticeable feature of the Chronomatic series is the left-side crown and right-side chronograph pushers. This unusual arrangement is a telltale sign of a Chronomatic movement in a watch of that era. Also notable in Chronomatic movements is the bi-compax arrangement with chronograph hours on the left and chronograph minutes on the right and date window at 6 00. Only the Chronomatic Calibre 15 features running seconds.

The Chronomatic was the result of a remarkable alliance of leading watch manufacturers. Dubois Dépraz first investigated the idea of combining a chronograph module of their design with a thin Büren micro-rotor automatic movement, but it was Heuer-Leonidas who drove the project. Heuer had the same idea for an automatic chronograph, approaching Dubois Dépraz independently with the idea. Once it appeared feasible, Heuer brought in Buren. Unable to afford the development and production of such a revolutionary movement, the consortium was forced to turn to rival Breitling, who agreed to join the effort. The final addition was Hamilton, who purchased Buren during this development project.

On March 3, 1969 the group presented the project to the world press simultaneously in Geneva, New York, Hong Kong and Beirut. Formerly code-named “Project 99”, the team unveiled the Chronomatic calibres at that event Calibre 12 was the main product, with Calibre 11 being a slower-running variant and Calibres 14 and 15 adding a 24 hour function and small seconds, respectively.

There is some controversy about who was truly first to launch an automatic chronograph and under what conditions. On January 10 of the same year, Zenith/Movado presented their own development of a self-winding chronograph movement, called "El Primero", i.e. “The First”. Both developments highlight, each for itself, the excellence of the Swiss watch making art. But at the same time, Seiko had quietly introduced their own 6139 automatic chronograph movement in Japan. Prototypes of all three movements were available at the same time, with Seiko and the Chronomatic team first to market in the summer. It was not until the end of 1969 that Zenith was able to release their El Primero to the market.

• See also automatic chronograph for a more complete story

• Calibre 11 19.800 A/h
• Calibre 12 21.600 A/h
• Calibre 14 like Cal. 12, with 24h GMT function
• Calibre 15 small second instead of 12h-counter

The individual movements were named according to the company which marketed them, so Buren 11 (Chronomatic), Breitling Calibre 11 (Chronomatic), Heuer Cal. 11,… Buren 12, etc. Note that some later calibres are marked “JRGK” instead.

• Main article TAG Heuer Calibre 11

In the 2000's, TAG Heuer reissued a number of watches that had previously used the Chronomatic Calibre 11 and Calibre 12 movements. These new watches were marketed as containing a “Calibre 11” or “Calibre 12” movement, but this calibre were based on an ETA or Sellita ebauche with a Dubois-Depraz module and was unrelated to the original Chronomatic. Confusingly, these movements are marked “Calibre 11” and “Calibre 12” on the rotor and some bear a “Heuer” (rather than modern “TAG Heuer”) badge.

The modern “Calibre 11” even appears correct, with the winding stem on the left and chronograph pushers on the right. The modern “Calibre 12” is more obvious, with all three on the right side.

• Project 99 -- The Race to Develop the World's First Automatic Chronograph