Established As Frères Baume in 1830 in Geneva, by brothers Louis-Victor and Célestin Baume, the manufacturer later on partnered with Paul Mercier in 1918, starting to be the Baume & Mercier we know currently. In the course of a particularly hard time period for that brand name, Baume & Mercier https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/