The Tank is a line of watches made by Cartier. It was created by Louis Cartier in 1917, and inspired by the new Renault tanks which Cartier saw in use on the Western Front, The prototype watch was presented by Cartier to General John Pershing of the American Expeditionary Force.
The Tank was introduced in 1918, and entered full production in 1919, when a total of six pieces were built. Its lines and proportions are similar to those of tanks found on First World War battlefields; it is both a square and a rectangle, and its strap is seamlessly integrated into vertical sidebars called "brancards". Since its inception, variations of the watch have been released by Cartier, including the Tank Louis in 1922, the Tank Americaine in 1989, and the Tank Francaise in 1996. The defining features of a tank watch include its bold Roman numeral dial with a chemin de fer chapter ring, sword-shaped blued steel hands, and a sapphire cabochon surmounted crown.