Founded As Frères Baume in 1830 in Geneva, by brothers Louis-Victor and Célestin Baume, the manufacturer afterwards partnered with Paul Mercier in 1918, starting to be the Baume & Mercier we know now. Throughout a particularly complicated period of time for your model, Baume & Mercier joined the Richemont group https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/