The Taurus was developed by adding cylinders to the existing single-row Aquila design and transforming it into a twin-row radial engine, creating a powerplant that produced just over 1,000 horsepower (750 kilowatts) with very low weight.

Bristol had originally intended to use the Aquila and Perseus as two of its major product lines in the 1930s, but the rapid increase in size and speed of aircraft in the 1930s demanded much larger engines.

The mechanicals from both of these designs were then put into two-row configurations to develop much larger engines, the Aquila becoming the Taurus, and the Perseus becoming the Hercules.

As the most important applications of this engine was in aircraft that flew at low altitude, development efforts focused on low-altitude performance.

In April 1940, a suggestion was made to replace the Taurus engines of the latter with the Pratt & Whitney R-1830 Twin Wasp, which had a slightly larger 48 in (1,200 mm) diameter, but this change was postponed to the autumn of 1941 while attempts were made to cure the Taurus's reliability problems, and later had to be temporarily reversed because of shortages of Twin Wasps.