Established As Frères Baume in 1830 in Geneva, by brothers Louis-Victor and Célestin Baume, the model afterwards partnered with Paul Mercier in 1918, starting to be the Baume & Mercier We all know today. In the course of a particularly difficult period of time for that model, Baume & Mercier https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/