Trojan underwent a number of transformations throughout its life before it ended up building bubble cars during the 1950s and '60s. It was founded by Leslie Hayward Hounsfield in a small workshop called the Polygon Engineering Works in Clapham, South London. He decided to build an economy car in 1910, and just before WW1 broke out in 1914, he was ready to put the idea into production. It wasn't until 1920 that the six cars were made in the Croydon factory, with the definitive production version being shown at the 1922 London Motor Show. The famous Trojan Utility Car followed in 1925.
The company struggled to gain traction throughout the 1930s, following Leslie Hounsfield's decision to leave the company. He set up a new enterprise making the Safari camp bed. Trojan continued to make vans until WW2, and following the war, van production restarted still with the original engine until 1952 when it was replaced by a Perkins diesel. In 1959 the company was bought by Peter Agg and from 1960 to 1965 he licence-built Heinkel bubble cars selling them as the Trojan 200. The company then acquired the rights to build the Elva Courier in 1962, making 210 cars between 1962 and 1965.