U.K. were a British progressive rock supergroup originally active from 1977 until 1980. The band was composed of singer/bassist John Wetton (formerly of King Crimson, Roxy Music, Bryan Ferry's band and Uriah Heep), keyboardist/electric violinist Eddie Jobson (formerly of Curved Air, Roxy Music and Frank Zappa's band), guitarist Allan Holdsworth (formerly of Tempest, Soft Machine, The New Tony Williams Lifetime and Gong) and drummer Bill Bruford (formerly a full member of Yes and King Crimson, and also a tour drummer for Genesis), who was later replaced by drummer Terry Bozzio (formerly of Frank Zappa's band). UK reformed with John Wetton, Eddie Jobson and Terry Bozzio for a world tour in 2012.
Singer/bassist John Wetton and drummer Bill Bruford had worked together in King Crimson from 1972 until 1974, when guitarist Robert Fripp disbanded the group. In July 1976, Bruford assisted Wetton on demos for a proposed solo album by the latter (a couple of these demos were later released on Monkey Business). In September 1976, they worked on forming a band with keyboardist Rick Wakeman, who had previously worked with Bruford in Yes. The project was stopped by Wakeman's label. According to Bruford, A&M Records were unwilling to let their 'star', Wakeman, walk off with a used, slightly soiled King Crimson rhythm section, and the idea failed.
Bruford and Wetton next asked guitarist Robert Fripp to reform King Crimson. When Fripp eventually declined, Bruford and Wetton decided that each would bring in a musician of his choice to form a new band. Wetton brought in keyboardist/violinist Eddie Jobson, whom Wetton knew from his work with Roxy Music in 1976 – stealing him from Frank Zappa. Bruford recruited guitarist Allan Holdsworth (formerly of Soft Machine and Gong) who had played guitar on Bruford's 1978 (recorded 1977) debut solo album, Feels Good to Me.