Started As Frères Baume in 1830 in Geneva, by brothers Louis-Victor and Célestin Baume, the model later partnered with Paul Mercier in 1918, turning out to be the Baume & Mercier we know these days. Through a particularly challenging period for that manufacturer, Baume & Mercier joined the Richemont team https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/