Baume & Mercier were founded in 1830 by Louis Victor and Pierre-Joseph-Celestin Mercier in a watchmaking house in Les Bois, in the Swiss Jura Mountains. In 1918 William Baume and Paul Mercier formed a partnership. In 1971 Baume & Mercier entered the electronic watch market with the Tronosonic, the first tuning fork watch movement. Since 1964 they have used the Greek letter PHI as their emblem. Official Website