Ernest Francillon (1834–1900) was a Swiss entrepreneur and a central figure in the history of the Longines watch brand. Born in Lausanne, he was the nephew of Auguste Agassiz, who had founded a watchmaking business in Saint-Imier in 1832. Francillon joined his uncle’s firm in 1852 after studying economics and completing an apprenticeship in watchmaking. His entry into the business marked a period of significant modernization and industrialization for the company.

By the early 1860s, as Agassiz’s health declined, Francillon took over the management of the firm. At the time, Swiss watchmaking relied on the établissage system, where individual parts were produced by specialized craftsmen in their homes and then assembled by trading offices. Recognizing the efficiency of American mass-production methods, Francillon envisioned a centralized factory system. In 1866, he purchased a plots of land in a location known locally as Les Longines (meaning “long meadows”) in Saint-Imier.

In 1867, the new factory was inaugurated, bringing all watchmaking stages under one roof. That same year, Francillon produced the company’s first movement, the Caliber 20A. To support his technical ambitions, he hired engineer Jacques David, whom he later sent to the 1876 World’s Fair in Philadelphia to study American manufacturing techniques. This research led to a pivotal report that influenced the transition of the Swiss watch industry toward mechanized production.

Francillon was also a pioneer in brand protection and marketing. In response to the rise of counterfeit timepieces, he trademarked the Longines name in 1880 and the winged hourglass logo in 1889. The logo remains the world’s oldest unchanged, active trademark registered with the World Intellectual Property Organization. Under his leadership, the brand became heavily involved in sports timing, producing its first chronograph movement, the 20H, in 1878 and serving as the official timekeeper for the first modern Olympic Games in 1896.

Beyond his industrial contributions, Francillon was a prominent figure in Swiss public life, serving in the National Council. He died on April 3, 1900, in Saint-Imier. His legacy is characterized by the transformation of Longines from a small trading office into a globally recognized manufacturer and his role in advancing modern Swiss horological practices.