Which war popularized Burberry's trench coat?

World War I popularized Burberry’s trench coat. The coat existed before the war, but its use by British officers in muddy, wet front-line trenches gave the garment its enduring name and reputation.

The trench coat evolved from earlier military raincoats and was designed as a lighter alternative to heavy serge greatcoats. Thomas Burberry had developed gabardine in the nineteenth century, and in 1901 he submitted a raincoat design for British Army officers to the War Office. During World War I, the design acquired military details such as epaulettes and D-rings for equipment, while its waterproof fabric helped protect officers from rain and wind.

The name does not mean the coat was invented entirely in a trench, and Burberry was not the only company associated with its origins: Aquascutum also claimed an early trench-coat history. After the war, veterans brought the garment into civilian life. Hollywood later amplified its image through figures such as Humphrey Bogart in Casablanca and Peter Sellers as Inspector Clouseau.