World War I coincided with the breakthrough of the wristwatch. New and trailblazing designs followed

in each subsequent decade. From the WatchTime Design Special 2019, here are our highlights.
1910s

Many soldiers in World War I preferred a quickly readable watch on the wrist to a timepiece safely tucked away in a pocket of their uniform jacket. One consequence of this was that after the Great War ended, the wristwatch became popular among men, many of whom had formerly belittled it as a feminine accessory. Wristwatches worn by soldiers on the front lines were typically equipped with protective grids to cover their crystals, which were not yet shatterproof.
Waltham World War I Military Watch
1920s

Wristwatches emerged as a genre in their own right during the Roaring ?20s, and Louis Cartier was among the trailblazers. He sketched his first Cartier Tank in 1917. The model was first produced in 1919 and it was given its elongated ?cintre?e? shape in 1921. Cartier Tank Cintré
1930s

The Art Deco style also influenced the design of wristwatches. With a rectangular case engraved with parallel lines at its upper and lower margins, the Reverso was a child of its era. LeCoultre was one of its producers.
LeCoultre Reverso
1940s

With the outbreak of World War II, the military again strongly influenced design in the ?40s. Pilots? watches like the Big Pilot?s Watch, which IWC first produced for the German Air Force in 1940, were easy to read thanks to their big cases and black dials...