The Chaîne d'ancre is the bracelet from which Hermès jewellery grew. It was designed in 1938 by Robert Dumas, a son-in-law of Émile-Maurice Hermès who joined the company in the 1930s and ran it from 1951 to 1978. Dumas based it on the links of a ship's anchor chain, and the design was soon picked up across the house.
Hermès' jewellery division has its roots in equestrian buckle-making; its first silver and leather bracelet, the Filet de selle, dates from 1927. The Chaîne d'ancre, though, became the emblem. Wikipedia describes it as the house's emblematic bracelet, and Sotheby's notes that its success inspired countless later Hermès pieces and accessories, from watch bracelets to belts and other chains.
Sotheby's calls the bracelet sporty yet elegant and very wearable. The original model is still made in 18-carat yellow gold, 18-carat rose gold and sterling silver, and gold examples regularly appear at auction, including in Christie's online jewellery sales of iconic designs.