InterCity (or, in the earliest days, the hyphenated Inter-City) was introduced by British Rail in 1966 as a brand-name for its long-haul express passenger services (see British Rail brand names for a full history).

In 1986 the British Railways Board divided its operations into a number of sectors ("sectorisation"). The sector responsible for long-distance express trains assumed the brand-name InterCity, although many services that were designated as such were assigned to other sectors (eg, London to King's Lynn services were transferred to the commuter sector Network SouthEast).

Divisions

InterCity was divided into the following divisions:

• East Coast: Services on the East Coast Main Line from London King's Cross to the North East, Yorkshire and eastern Scotland.
• West Coast: Services on the West Coast Main Line from London Euston to the West Midlands, North Wales, the North West and southern Scotland, including overnight sleeper services to Scotland.
• Midland: Services on the Midland Main Line from London St Pancras to the East Midlands and parts of Yorkshire
• Great Western: Services on the Great Western Main Line from London Paddington to the West Country and South Wales, including overnight sleeper services to the West Country.
• Great Eastern: Services on the Great Eastern Main Line from London Liverpool Street to East Anglia and Essex.
• Cross-Country: Services between city pairs that use a combination of the various main lines, but in general do not call at any London terminus; many of these served the Cross-Country Route.
• Gatwick Express: Shuttle service between London Victoria and Gatwick Airport.

The InterCity sector was also responsible for Motorail services to and from London.

Operations

It operated High Speed Trains under the brand-name "Inter-City 125", as well as InterCity 225s and various other locomotive-hauled trains. The "125" referred to the trains' top speed in miles per hour (mph), equivalent to 201 km/h, whereas "225" referred to the intended top speed in km/h (equivalent to 140 mph) and for signalling reasons their actual speed limit was the same 125 mph. InterCity 250 was the name given by InterCity to the proposed upgrade of the West Coast Main Line in the early 1990s.

All InterCity day services ran with a buffet car and the majority ran at speeds of 100 mph or above. If expresses on other sectors are included, there was a period in the early 1990s when British Rail operated more 100 mph services per day than any other country. Special discounted fares, including the Super Advance and the APEX, were available on InterCity if booked ahead. Great Western: Services on the Great Western Main Line from London Paddington to the West Country and South Wales, including overnight sleeper services to the West Country. Great Eastern: Services on the Great Eastern Main Line from London Liverpool Street to East Anglia and Essex. Cross-Country: Services between city pairs that use a combination of the various main lines, but in general do not call at any London terminus; many of these served the Cross-Country Route. Gatwick Express: Shuttle service between London Victoria and Gatwick Airport.

Main Destinations

East Coast Mainline: London Kings Cross, Stevenage, Peterborough, Grantham, Newark North Gate, Doncaster, Hull, Wakefield Westgate, Leeds, York, Darlington, Durham, Newcastle, Berwick-upon-Tweed, Edinburgh, Glasgow Central, Dundee, Perth, Aberdeen, Inverness.

West Coast Mainline: London Euston, Watford Junction, Milton Keynes Central, Rugby, Coventry, Birmingham International, Birmingham New Street, Wolverhampton, Crewe, Stoke-on-Trent, Macclesfield, Wilmslow, Stockport, Manchester Piccadilly, Runcorn, Liverpool Lime Street, Llandudno Junction, Holyhead, Warrington Bank Quay, Wigan North Western, Preston, Lancaster, Oxenholme: The Lake District, Carlisle, Motherwell, Glasgow Central.

Great Western Mainline: London Paddington, Reading, Didcot Parkway, Swindon, Bath Spa, Bristol Parkway, Bristol Temple Meads, Newport, Cardiff Central, Port Talbot Parkway, Swansea, Taunton, Tiverton Parkway, Exeter St. David's, Newton Abbot, Paignton, Totnes, Plymouth, Bodmin Parkway, St. Austell, Truro, Penzance.

Midland Mainline: London St. Pancras, Luton, Bedford, Wellingborough, Kettering, Market Harborough, Leicester, Loughborough, Nottingham, Derby, Chesterfield, Sheffield.

Cross Country Route: Penzance, St. Austell, Plymouth, Exeter St. David's, Taunton, Bristol Temple Meads, Bristol Parkway, Cardiff Central, London Paddington, Poole, Bournemouth, Southampton, Brighton, Gatwick Airport, Reading, Oxford, Cheltenham Spa, Coventry, Birmingham International, Birmingham New Street, Wolverhampton, Stafford, Crewe, Stoke-on-Trent, Macclesfield, Stockport, Manchester Piccadilly, Runcorn, Liverpool Lime Street, Preston, Carlisle, Glasgow Central, Derby, Sheffield, Doncaster, Leeds, York, Darlington, Durham, Newcastle, Berwick-upon-Tweed, Edinburgh, Kirkcaldy, Dundee, Arbroath, Aberdeen.

Great Eastern Mainline: London Liverpool Street, Chelmsford, Colchester, Ipswich, Stowmarket, Diss, Norwich. Some trains did terminate at Harwich international for the ferries at Harwich docks.

Livery

The original InterCity livery consisted of standard British Rail corporate blue and grey with the brand "Inter-City" added in white lettering on each coach. The power cars at each end of Inter-City 125 trains had extensive yellow panels, hence the nickname "flying bananas". A separate InterCity livery was introduced in 1986 after sectorisation, which consisted of dark grey on white with a red stripe. There were several variations:

• Executive - introduced in 1984, based on the APT-P livery. It consisted of a dark grey upper body, an off-white lower body, and horizontal red and white below-window bodyside stripes. On HSTs, half-yellow front ends wrapped around the lower cab ends. InterCity branding was on the upper grey body, with white numbers carried on the upper grey cabside.
• ScotRail - as Executive livery, but with red stripe replaced by a light blue stripe, and ScotRail branding.
• Mainline - introduced in 1988. As Executive livery, but minus the branding and with full-yellow front ends.
• Swallow - final version, introduced in 1989. As Mainline livery, but with white lower body (on locomotives), half-yellow front end, InterCity branding and Swallow logo on upper grey bodyside, and black lower cabside numbers.

The success of the HST trains and the investment in electrification schemes, resulting in shorter and more reliable journey times, coupled to innovative marketing led to InterCity becoming one of the great successes for British Rail in the 1980s. Patronage increased markedly, and it soon became the most profitable part of the state-owned rail operator, and cross-subsidisation from InterCity's profits was used to safeguard the future of unprofitable (but necessary) rural routes which had been under threat from closure since the Beeching Axe of the 1960s.

Privatisation

After the privatisation of British Rail, InterCity trains were divided up into several franchises. The Caledonian Sleeper are transferred to ScotRail, now First ScotRail.

Divisions	Original Franchise	Currently
East Coast	GNER	Then passed to National Express East Coast
West Coast	Virgin Trains	Remained unchanged
Midland	Midland Mainline	Then passed to East Midlands Trains
Great Western	Great Western Trains	Renamed First Great Western. Also operates Night Riviera from London to Penzance
Gatwick Express	Gatwick Express	Merged into Southern and now a sub-brand
CrossCountry	Virgin Trains	Then passed to CrossCountry
Great Eastern	Anglia Railways	Then merged into National Express East Anglia