Which brand helped popularize the trench coat?

The trench coat was developed as an alternative to the heavy serge greatcoats worn by British and French soldiers in the First World War. The invention of the trench coat is claimed by two British luxury clothing manufacturers, Burberry and Aquascutum, with Aquascutum's claim dating back to the 1850s. Thomas Burberry invented the gabardine fabric in 1879 and submitted a design for an Army officer's raincoat to the United Kingdom War Office in 1901.

The trench coat became an optional item of dress in the British Army and was obtained by private purchase by officers and Warrant Officers Class I who were under no obligation to own them. No other ranks were permitted to wear them. Another optional item was the British Warm, a wool coat similar to the greatcoat that was shorter in length, also worn by British officers and Warrant Officers Class I as an optional piece.