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