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, getting the Baume & Mercier We all know now. Throughout a very complicated period of time for the model, Baume & Mercier joined the Richemont group https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/