Rolls-Royce Limited increase its own production rates. By the late 1920s, aero engines made up most of Rolls-Royce's business. Henry Royce's last design was the Merlin aero engine, which was first flown in prototype form in 1935, although he had died in 1933. This was developed from the R engine, which had powered a record-breaking Supermarine S.6B seaplane to almost in the 1931 Schneider Trophy. The Merlin was a powerful supercharged V12 engine and was fitted into many World War II aircraft: the British Hawker Hurricane, Supermarine Spitfire, de Havilland Mosquito (twin-engine), Avro Lancaster (four-engine) (a development of the Avro Manchester with
Rolls-Royce–Bentley L-series V8 engine the car manufacturing business, and Rolls-Royce plc were not prepared to allow Volkswagen to license this crucial intellectual property. Three way negotiations between Volkswagen Group, BMW and Rolls-Royce plc resulted in BMW purchasing the rights to the Rolls-Royce brand and badge from Rolls-Royce plc for £40m. Rolls-Royce plc, who had been involved in an aero engine joint venture with BMW since 1990 consistently supported their long time business partner during the bidding process for Rolls-Royce and Bentley Motors. German politicians brokered a deal between Volkswagen Group and BMW to ensure BMW would continue to supply engines, transmissions and key components