Free Overnight Shipping
Watch Certification Services of America 100% Certified Authentic

How Aegler Became Rolex’s In-House Movement Maker

Paul Altieri

It may come as a surprise to some, but it was only in 2004 when Rolex outright purchased the movement manufacturing facility that makes the calibers for Rolex watches. Prior to that, the company that manufactured movements for Rolex was, in fact, a separate entity owned by the Borer/Aegler family. From Aegler to Rolex Bienne to finally, a subsidiary of Rolex, discover the history of Rolex’s movement production.

The caliber 1570 movement inside a vintage Rolex Submariner ref. 1680.

The Early Rolex Years, Hans Wilsdorf and Aegler

When Hans Wilsdorf established his watch company in London in 1905, he was in need of a supplier who could make miniaturized movements for wristwatches. Remember, this was an era where large movements for big pocket watches were the standard.

Older Rolex movements are often less decorated and more utilitarian in appearance than their modern counterparts.

Consequently, he turned to the Aegler family movement makers based in Biel/Bienne (Biel is the German name for the city and Bienne is the French name), who specialized in small mechanical movements. Hermann and Hans Aegler were at the helm of the movement manufacture, having taken over from their mother (who took over after her husband, Jean Aegler died in 1891).

If we look at the first Swiss Certificate of Chronometric Precision awarded to a Rolex watch in 1910, we see that the name on the certificate is actually “Les Fils de Jean Aegler” – French for “The Sons of Jean Aegler.” The movement maker was renamed and registered as Aegler S.A. in 1913.

Older Rolex chronograph movements were often based on Valjoux or Zenith calibers.

From the start, the relationship between Aegler and Rolex was strongly intertwined. After Rolex’s operations moved from London to Geneva in 1919, Hermann Aegler became a Rolex board member when he bought a large share of Rolex stock in the 1920s (only to sell it back to Rolex later).

Hermann Aegler’s nephew, Emile Borer became technical director of the family business in the early 1930s. Aegler S.A. was renamed Manufacture des Montres Rolex SA (but still wholly owned by the Aegler/Borer family) in the mid-1930s, with an agreement to be Rolex’s exclusive movement supplier. The few exceptions to this agreement were the Valjoux-based and the Zenith El-Primero-based chronograph movements (fitted in the Rolex Daytona) that came later.

The caliber 1570 movement inside a vintage Rolex Date ref. 1500

Rolex Bienne and Rolex Genève

The Aegler/Borer-owned movement making facility was almost always referred to as Rolex Bienne, and to the vast majority of outsiders, it simply looked like a subsidiary of Rolex Genève. However, in truth they were indeed two separate entities, albeit entirely inseparable.

The caliber 1555 movement inside a vintage Rolex Day-Date President ref. 1803.

Under the leadership of Patrick Heiniger, Rolex Genève purchased Rolex Bienne from the Borer family in 2004 for a reported CHF 1 billion. This was about the same time that Rolex was snapping up other suppliers like dial manufacturer Beyeler, winding crown maker Boninchi, and bracelet producer Gay Frères. The acquisition of the movement facility was an important step for Rolex SA’s strategy to become a completely vertically integrated watch manufacturer.

In 2009, Rolex began work on expanding its site in Bienne; and in 2012, Rolex unveiled its new its new state-of-the-art movement production building. And now, the Crown can truly say that all of their watch movements are entirely designed and produced in-house.

The caliber 1520 movement inside a Rolex Submariner ref. 5513.
Paul Altieri

Paul is the company's Founder and CEO. He is responsible for all the day to day activities from purchasing, receiving, marketing and sales. Paul is a graduate of Boston College 1979 and resides in California with his family.

  1. So in the years prior to 2004. was rolex engineering or designing them or was it all Borer/Aegler family designs and engineering? and rolex just buy them like a microbrand would today?

    • Although Rolex did not own Aegler outright until 2004, they were still designing and engineering the movements before purchasing the manufacturing facilities. By contrast, many microbrands today use off-the-shelf movements from various manufacturers (often either ETA, Sellita, Seiko, or Miyota). However, these movements are not of their own designs and they are used in many different watches from other brands (ie. you will find watches from countless brands fitted with the ETA 2824 movement). However, Rolex’s in-house movements are actually in-house creations and as such, they are not found in any other brand’s watches (ie. the Rolex Cal. 3135 will only be found inside Rolex watches).

      • So it would be a fair statement that Rolex designed all their own movements and Aegler merely manufactured them to spec?

        • Yes, although it is equally possible that Rolex also used Aegler for the design and development of its movements (based on Rolex-supplied rough specs/parameters), and then had an exclusive arrangement with Aegler where any of the Rolex designs and technology could not be used in any other watches. This is a rather common practice for brands that are part of a larger parent group, where one of the other brands is exclusively a movement manufacturer (for example, how ETA is part of the greater Swatch Group).