In 1907, Charles Rolls, whose interests had turned increasingly to flying, tried unsuccessfully to persuade Royce and the other directors to design an aero engine. When World War I broke out in August 1914, Rolls-Royce (and many others) were taken by surprise. As a manufacturer of luxury cars, Rolls-Royce was immediately vulnerable, and Claude Johnson thought the bank would withdraw its overdraft facility on which Rolls-Royce depended at that time. Nevertheless, believing that war was likely to be short-lived the directors initially decided not to seek government work making aero engines. However, this position was quickly reversed and Rolls-Royce was persuaded by the War Office to manufacture fifty air-cooled V8 engines under licence from Renault. Meanwhile, the Royal Aircraft Factory asked Rolls-Royce to design a new engine. Despite initial reluctance, they agreed, and during 1915, developed Rolls-Royce's first aero engine, the twelve-cylinder Eagle. This was quickly followed by the smaller six-cylinder Hawk, the Falcon and, just before the end of the war, the larger Condor.