Jaguar Cars, formerly known as SS Cars before the company renamed itself in 1945, had made its post-war name with the XK120 sports car, launched in 1948 and powered by a new twin overhead-camshaft 3.5-litre straight-six engine designed by William Heynes, Walter Hassan, and Claude Baily. The engine had been conceived during wartime, with engineers working on the design during fire-watch duties at the Coventry factory. Lyons' vision for the company relied on using motorsport as a proving ground to demonstrate the quality of Jaguar's engineering to international buyers, particularly in the American market.
Jaguar developed a purpose-built racing car, the C-Type (for Competition), derived from the XK120 but substantially lighter and more aerodynamically refined. The C-Type debuted at the 24 Hours of Le Mans in 1951 and won outright, delivering Jaguar's first Le Mans victory. The result announced Jaguar as a serious force in international endurance racing and generated significant commercial interest in the company's road cars.
In 1953 Jaguar returned to Le Mans with revised C-Types and won again. The 1953 victory confirmed the win of two years prior as no accident — Jaguar had the machinery, drivers, and operational competence to compete at the top level of sportscar racing.
Jaguar developed the D-Type successor for the 1954 and subsequent seasons, a car with more advanced aerodynamics including a distinctive dorsal fin behind the driver's head. The 1955 Le Mans race produced a Jaguar victory but one that was overshadowed by the worst accident in motorsport history — the crash involving Pierre Levegh's Mercedes, which killed Levegh and approximately eighty spectators in the grandstand. The race continued despite the disaster, and a Jaguar driven by Mike Hawthorn and Ivor Bueb won, but the event's outcome was secondary to the human tragedy that unfolded.
Jaguar wound down its official factory racing effort in the mid-1950s, but D-Types continued to race competitively in the hands of privateers. The Scottish team Ecurie Ecosse — which raced in dark blue livery — ran D-Types to overall Le Mans victories in both 1956 and 1957, extending Jaguar's Le Mans legacy through customer machinery after the works team had stepped back. This privateer success illustrated both the capability of the D-Type design and Jaguar's indirect approach to continuing competition without the full cost of a factory programme.
The XKSS, a road-legal version of the D-Type, was developed briefly before a factory fire in February 1957 destroyed nine of the twenty-five cars being converted. Only sixteen XKSS examples were ultimately completed.
Jaguar's 1950s racing programme produced five 24 Hours of Le Mans victories — 1951, 1953, 1955, 1956, and 1957 — making the marque one of the defining forces in the sport's golden era. William Lyons' strategy of using motorsport to build the Jaguar brand worked exactly as intended: the company's racing successes supported strong sales of road cars, particularly in the American market, where Jaguar's combination of performance and value attracted significant attention. The C-Type and D-Type have since become among the most coveted historic racing cars in the world, representing a period when a British manufacturer from Coventry with limited resources could challenge and defeat the major factory programmes of Italy, France, and Germany at the world's most demanding endurance events.