The brothers Charles Antoine and François Ulysse LeCoultre established the watch company LeCoultre in Le Sentier, in the Vallée de Joux, in 1833. The former was an accomplished craftsman who devoted all of his time and energy to creating novel production and manufacturing techniques. He achieved the first mechanical component measurement to the thousandth of a millimeter in 1844 with his Millionometer. Developed in 1847, his crown winding mechanism eliminates the need for the winding key that was previously necessary for all other watches. Thanks to this new invention, LeCoultre was able to win his first gold medal at the 1st World Exhibition in London with a pocket chronograph.