It’s entirely possible that without the conflicts of the late 19th and early 20th centuries, we wouldn’t have wristwatches at all – at least, not as we know them today. The specialist demands of pilots, divers and infantrymen dictated the forms of their watches and laid down templates that live on today in the watches of IWC Schaffhausen, Panerai and many more besides.

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Kaiser Wilhelm I orders 2,000 watches from Girard-Perregaux for the German naval forces. Fitted with a wrist strap and a crude protective mesh, they are considered by many to be the first example of a mass-produced wristwatch.

Less a military watch and more a military-influenced watch, Mr Louis Cartier’s Tank makes its debut – a square-faced wristwatch that takes its inspiration from the imprints left by the tracks of the very first Renault tanks as they roll across the Western Front. One of the 20th century’s most iconic dress watches, the Tank is still in production today.

The German aviation ministry unveils plans for a navigator’s watch, the giant Beobachtungsuhr or “B-Uhr”, which features a leather strap long enough to be worn over a flight jacket and an oversized crown designed to be wound while wearing thick gloves. Manufacturing contracts are awarded to five watchmakers, including IWC. In 2002, the brand releases the Große Fliegeruhr or Big Pilot’s Watch, which takes its design cues from the B-Uhr.

Panerai produces ten prototypes of its now iconic Radiomir, a cushion-shaped diving watch designed for the Italian Royal Navy’s elite frogman commando unit. The dial is coated in Panerai’s patented Radiomir paste, a luminescent, radium-based substance now understood to be dangerously radioactive. (Modern versions use Super-LumiNova instead.)

At the outbreak of WWII, the British Ministry of Defence lays down specifications for a field watch (abbreviated WWW for “wrist, watch, waterproof”) and commissions 12 Swiss manufacturers to produce it. These watches are highly prized by modern watch collectors, who know them as “The Dirty Dozen”. Modern reproductions include the Broadsword from Bremont.

The US Army introduces specifications for its own field watch. Mass-produced by Elgin, Bulova and Waltham, the A-11 spec proves instrumental in coordinating military attacks during the latter stages of WWII, earning itself the nickname “the watch that won the war”.

The British Ministry of Defence lays down plans for a new navigator’s wristwatch standard, the Mk XI, which is produced from 1948 to 1953 by IWC and Jaeger-LeCoultre. In 1994, IWC releases a civilian follow-up, the Mk XII, beginning a tradition that continues today with the most recent model, Mk XVIII.