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