Started As Frères Baume in 1830 in Geneva, by brothers Louis-Victor and Célestin Baume, the brand name later on partnered with Paul Mercier in 1918, becoming the Baume & Mercier We all know nowadays. Throughout a very challenging time period for that model, Baume & Mercier joined the Richemont group https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/