Parkes first entered a World Championship Grand Prix at Aintree in 1959 driving a Formula 2 (F2) Fry-Climax 1.5-litre Straight-4. However he did not qualify and returned to sportscars thereafter, apart from a single outing at Mallory Park in 1962 with a Bowmaker Cooper. Following his success with Ferrari sportscars, Parkes joined Ferrari officially, in 1963 as development and reserve driver, and over the following seasons became recognised as a leading sports car driver. When John Surtees unexpectedly left Ferrari in 1966, Parkes was promoted to the Grand Prix team and with an extended chassis to accommodate his height of six feet four inches, was immediately successful, finishing in second place in the 1966 French Grand Prix at Reims. Jack Brabham won the race with his teammate, Denny Hulme, third, in their Brabham–Repcos. However this was followed by two retirements before another second place at Monza where he also took pole position. Parkes won an international Formula One race at Silverstone by one third of a lap over Brabham in April 1967.The 52 lap race was the first Formula One contest for Parkes in his native country. He completed the 152.36 mile competition in 1:19:39.25 with an average speed of 114.65 m.p.h.