The Eagle VIII was the first aero engine designed by Rolls-Royce.  They used the 40/50 hp Silver Ghost engine as the basic platform for the new V-12 which was intended to provide a powerful and reliable liquid-cooled military aero engine which was not available in the UK at the outbreak of the First World War in August 1914.  Rolls-Royce initially produced a small batch of French Renault V-8 aero engines on the condition that this would be a trial project for the new engine. 

The prototype Eagle engine was ready for testing at Rolls-Royce's Derby works in February 1915.  The design process was complicated by the locations of the design team and the factory being 200 miles apart.  Drawings and wooden patterns were sent backwards and forwards until Royce was satisfied and drawings were prepared for around 2,000 components.

The Eagle VIII engine featured forged aluminium pistons and pressed steel water jackets to save weight. Power output exceeded the target of 200 hp and was soon increased to 300 hp at 2000 rpm.  The first air test using a twin-engine Handley Page bomber took place on 18 December 1915 at Hendon near London.  The Eagle VIII (350 hp) engine was the most widely used version being installed in Airco DH.4 and the V/1500 series Vickers Vimy bomber and all the South African Air Force DH.4 aircraft were equipped with this engine.  The particular engine on display came from the Silver Queen and Silver Queen II aircraft flown by Sir Pierre van Ryneveld and Brand when they made their epic flight from England to South Africa.