Vacheron Constantin SA (vaʃəʁɔ̃ kɔ̃stɑ̃tɛ̃) is a Swiss luxury watch and clock manufacturer founded in 1755. Since 1996, it has been a subsidiary of the Swiss Richemont Group. Vacheron Constantin is the second oldest Swiss manufacturer and one of the oldest watch manufacturers in the world with an uninterrupted watchmaking history since its foundation in 1755. It employs around 1,200 people worldwide as of 2018, most of whom are based in the company's manufacturing plants in the Canton of Geneva and Vallée de Joux in Switzerland. Vacheron Constantin is a highly regarded watch manufacturer. The Vacheron Constantin pocket watch No. 402833 (1929), which was owned by King Fuad I of Egypt, ranks as one of the most expensive watches ever sold at auction, fetching US$2.77 million (3,306,250 CHF) in Geneva on April 3, 2005. In 2015, Vacheron Constantin introduced the pocket watch Reference 57260, which currently holds the title of the most complicated mechanical watch ever made, with 57 horological complications. The business was founded in 1755 by Jean-Marc Vacheron, an independent watchmaker in Geneva, Switzerland. He was a close friend of leading Enlightenment philosophers Jean-Jacques Rousseau and Voltaire due to their common interests in philosophy, science and watchmaking. In 1770, Vacheron's company created the world's first horological complication, and nine years later he designed the first engine-turned dials. The son of Jean-Marc Vacheron, Abraham Vacheron took over the family business in 1785. In 1810, Jacques-Barthélemy Vacheron, the grandson of the founder, became the head of the company. He was the first to initiate the company's exports to France and Italy. Later, Jacques-Barthélemy realized that he was not able to handle the business alone. In order to travel overseas and sell the company's products, he needed a partner. Consequently, in 1819, François Constantin became an associate of Vacheron. The company continued its activities under the new name Vacheron & Constantin.