From 2001 until 2013, the primary ITV channel was called ITV1. In 2004, Granada Television acquired Carlton Communications to form ITV plc.
ITV is the biggest and most popular commercial television channel in the United Kingdom. ITV and its predecessor channels have contended with BBC One for the status of the UK's most-watched television channel since the 1950s. However, in line with other terrestrial channels, ITV's audience share has fallen as a result of the availability of multi-channel television in the UK.
Following the creation of the Television Act 1954, the establishment of a commercial television service in the UK began.
The Independent Television Service, abbreviated ITV, was made up of distinct regions, with each region run by different franchisee companies. The three largest regions, London, the Midlands, and the North of England, were subdivided into weekday and weekend services, with a different company running each. ITV existed in a region-heavy form from its inception through to the 2000s, although the switch to a single unified service was gradual.
ITV1 became the generic on-screen brand name used by the twelve franchises of the ITV Network in the United Kingdom. The ITV1 brand was introduced in 2001 by Carlton- and Granada-owned franchises initially used alongside the local regional name, such as "ITV1 Anglia" and "ITV1 Meridian".
However, it became the sole on-air identity in 2002 when the two companies decided to create a single unified playout of the channel, with regional references only used prior to regional programmings, such as local news and weather.
Carlton and Granada went on to merge in 2004, creating ITV plc, which now owns thirteen of the fifteen regional ITV licenses.
The ITV1 name was only used in England, Wales, Southern Scotland, and the Isle of Man, until Channel Television adopted the name in January 2006, bringing it to the Channel Islands. As national continuity is often used on Channel Television, ITV1 national branding had been seen on the station for several years previously.
ITV Wales & West was the only exception, using the name ITV1 Wales at all times for the Welsh part of its broadcast area, as it has a higher regional commitment. Latterly, the ITV1 Wales name was only used on break-bumpers and regionally advertised programs until 2013. Non-ITV plc-owned licensees on the ITV network generally did not refer to the ITV name.
The network production arms of the ITV-plc owned licenses have been gradually combined since 1993, to eventually form ITV Studios.