 Originally designed as turbotrains to be powered by gas turbines, TGV prototypes evolved into electric trains with the 1973 oil crisis.In 1976 the SNCF ordered 87 high-speed trains from GEC-Alsthom.Following the inaugural service between Paris and Lyon in 1981 on the LGV Sud-Est (LGV for "Ligne à Grande Vitesse"; "high-speed line"), the network, centered on Paris, has expanded to connect major cities across France (including the likes of Marseille, Lille, Bordeaux, Strasbourg, Rennes, Montpellier) and in neighbouring countries on a combination of high-speed and conventional lines.