The InterCity 125s were introduced into passenger service from 1976 and instantly revolutionised rail travel. As the world's fastest diesel trains, they heralded significant journey-time reductions, reversing declining demand without requiring the construction of new lines to accommodate them. At each end of the train a sleek 2,250 hp power car with its iconic shape made the 125 an instantly recognisable train, while the distinctive noise produced by the original turbocharger resulted in a train that commanded attention wherever it went. Privatisation saw the 125s refurbished and repainted as they remained at the forefront of their new owners' fleets. 125 Group was formed in 1994 by a small group of enthusiasts to provide a focus point for information and news regarding the HST. Since then it has grown into a preservation organisation with over 500 members, restoring and now operating the prototype HST power car No. 41001, owning and operating three Mk 3 coaches and still providing a quality quarterly magazine. With an array of fascinating photographs and insights, 125 Group tells the story of an enduring icon of Britain's railways.