The house of Jaeger-LeCoultre

Antoine LeCoultre set up a workshop in the Vallée de Joux in 1833 and spent the century solving problems nobody else had got to: a tool that measured a micron, in 1844, and a keyless winding system of his own. The firm's partnership with the Paris watchmaker Edmond Jaeger gave it the name it carries from 1937.

It is often called the watchmaker's watchmaker, and the phrase is literal. Jaeger-LeCoultre has supplied movements to Patek Philippe, Audemars Piguet and Vacheron Constantin, and has produced well over a thousand calibres of its own.

Its most recognisable watch exists for a frivolous reason. In 1931 British officers in India wanted something that would survive a polo match, so the Reverso was built with a case that flips over to hide its own dial. It remains one of the few genuinely Art Deco objects still in production.