D. Napier and Son began building aircraft engines in the World War I era. The Lion series was produced from 1917 until 1932 for military, commercial, and racing aircraft. Napier’s World War II era Sabre engines also powered a number of aircraft. Intended for use in long-range aircraft at the end of World War II, the Nomad was an engineering tour-de-force, although being one of the most complex aircraft engines ever built. Napier designed the Nomad to have the lowest possible fuel consumption by compounding a two-stroke diesel engine with a gas turbine and transmitting the power through a propeller.
The Nomad II, a simplified version of the original design, appeared in 1951 and was intended for the four-engine Avro Shackleton long-range patrol bomber. However, a single Nomad II flew only briefly, in the nose of an Avro Lincoln bomber. Napier cancelled the program in 1955 because the Nomad could not compete with gas turbine engines.