A Rolex in sheep's clothing? The history of Rolex is closely linked with Aegler who manufactured the watches for Rolex in the 1920s and 30s. Aegler manufactured watches for both Gruen and Rolex in their Bienne factory in Switzerland. Rolex and Gruen came to a mutual agreement with Aegler that Gruen would only sell their watches in the US whilst Rolex would sell to the rest of the world. In the 30s Gruen sold their shares back to Aegler and by 1936 Rolex had agreed to take the complete production of the Aegler factory. This watch has the same movement as the Rolex Prince (Calibre 877) and would easily be mistaken for it's more commonly seen relative. Known and promoted as a doctor's watch it was exceptionally accurate and was the first wristwatch movement to be officially chronometer-certified without being adjusted for the test. This particular watch is really a thing of incredible beauty and not bad for something around 90 years old!