The Siddeley-Deasy was built by the British automobile company Deasy Motor Company from 1906 to 1912 in a Coventry factory that had previously been used to build the Iden automobile. Coventry, England was larger home to the Jaguar marque. The Siddeley-Deasy cars were sold in England and exported to the British colonies, as well. The Siddeley-Deasy used Rover chassis and Daimler and Aster motors. In 1919, the company merged with Armstrong and the car became the Siddeley-Armstrong.
The company changed its name from Deasy to Siddeley-Deasy when J.D. Siddeley joined the company. During World War I the company grew to 5,000 workers producing ambulances and air-craft engines.
The car is powered by a 2.9-liter, four-cylinder motor that develops 14 to 20 horsepower.
This car was located a few years ago in a barn in Christchurch, New Zealand In 2002 where it had been stored since the 1960's following rescue from many years of outside storage. It is the only known Siddeley-Deasy in the United States. The current owner undertook the restoration in 2003 and did most of the work himself.