The original business was established in 1912 by Thomas Fredrick Watson as the Patent Collapsible Sidecar Company Ltd. at Balsall Heath, Birmingham, England.

Early sidecars were initially built with wickerwork bodies, which were then replaced by ash frames with plywood or steel panels.

[2] Watsonian was an early supplier to the Swallow Sidecar Company, which after World War II was renamed to Jaguar Cars.

[3] In the 1970s, Watsonian used their expertise in GRP to diversify into production of hardtops for Land Rover and for sports cars.

[1][4] When the Land Rover contract ended in 1981, Watsonian was forced to scale back production and make several staff redundant.