Intercity was a name seen long before sectorisation, initially given to British Rail’s long haul express passenger services connecting the many cities across England, Scotland and Wales. Inter-City, two words, operated service in the early days with the vast selection of diesels available following the modernisation plan. During this era each of the 4 regions would operate their own Inter-City services, with each choosing to operate different locomotives on their services. Eventually however all long haul express services branded as Inter-City were combined into the new Intercity sector, which then operated from the 1980s into the 1990s.

By the 1980s and the introduction of the new Intercity brand, Inter-City operations had become synonymous with the High Speed Train, which had been marketed as the InterCity 125 since it entered service in 1976. Thanks to their high top speed journey times to improved substantially, which led to increased use of Intercity services. The High Speed Train operated the majority of routes served by Intercity by the start of the Intercity sector, with only the West Coast Main Line and Great Eastern Main Line retaining locomotive hauled service with electric traction thanks to their electrification during the 1960s and 1970s.

Alongside the introduction of the High Speed Train was the development of the much less successful Advanced Passenger Train. A long development ended in the prototype trains proved to be unpopular and unreliable when initially introduced in 1981. Intercity eventually reintroduced the trains, however only for a limited time. The APT ultimately never made it beyond 1984, although much of the technology developed during the project was implemented on the Intercity 225, which was introduced onto the East Coast Main Line during the later years of Intercity. 

Following privatisation the sector was separated into 8 franchises, the success of Intercity as an entity meant many operators bid on the new franchises with few seeing success in the initial franchise model before many franchises saw reshuffling during the 2000s. Intercity today lives on as a charter company, part of Locomotive Services Group. Many of the original locomotives used by Intercity on operations during the sectorisation era, including the Class 86, 87 and 90, are operated by the new brand, as well as diesel locomotives which were used in the early days of Inter-City service in the 1960s and 1970s.