Léon Breitling was born on 27 January 1860 and was drawn to watchmaking young, serving his first apprenticeship as a teenager. In 1884, aged 24, he set up his own workshop in Saint-Imier, in the Bernese Jura, specialising in chronographs, counters and precision timing instruments for sport, science and industry.
In 1892 he moved the business to larger premises in La Chaux-de-Fonds under the name Léon G. Breitling S.A. Montbrillant Watch Manufactory, where it grew to about sixty employees. The firm's timers followed the rise of competitive sport, motoring and early aviation. Léon Breitling died on 11 August 1914, and the company passed to his only son, Gaston. A year later, in 1915, the firm introduced the first independent chronograph push-piece for wristwatches, the first of a series of innovations that shaped the modern wrist chronograph.