Louis Brandt was 23 when, in 1848, he opened a comptoir d'établissage in La Chaux-de-Fonds, in the canton of Neuchâtel. Under this pre-industrial system he gave out the stages of manufacture to independent local craftsmen and assembled the parts into key-wound precision pocket watches, which were sold under the name "Louis Brandt". He sold them from Italy to Scandinavia, with England as his chief market.
His sons Louis-Paul and César joined him in 1877, and the firm became Louis Brandt & Fils. In 1879 the two sons decided to move into industrial "American-style" manufacturing and, finding La Chaux-de-Fonds short of skilled labour and space, settled in Biel/Bienne, where from January 1880 they made their first machine-made calibre. Casadi has not verified Louis Brandt's date of death. French Wikipedia has a separate article on a Louis Brandt (1800–1866), a La Chaux-de-Fonds watch merchant and radical politician; his age does not match Omega's founder, and Casadi does not treat them as the same person. English Wikipedia's statement that "Louis Brandt, the founder" made a minute-repeating wristwatch with Audemars Piguet in 1892 is treated by Casadi as uncertain.