Formed by Sumner and Hook after the two attended a Sex Pistols gig, Joy Division soon moved beyond their punk roots to develop a sound and style that made them one of the pioneers of the late-1970s post-punk movement. The band's self-released 1978 debut EP, An Ideal for Living, drew the attention of the Manchester television personality Tony Wilson, who signed the group to his independent label Factory Records. Joy Division's debut album Unknown Pleasures, recorded with producer Martin Hannett, was released in 1979 to critical acclaim.
As the band's popularity grew, singer Curtis suffered from personal problems that included depression, a failing marriage, and epilepsy. He found it increasingly difficult to perform live concerts, during which he sometimes suffered seizures. In May 1980, on the eve of the band's first American tour, Curtis committed suicide, aged 23. The band's second and final album, Closer, was released two months later; the album and preceding single "Love Will Tear Us Apart" became the band's highest charting release.
Following Curtis's death, the remaining members continued as New Order, subsequently achieving critical and commercial success.
On 20 July 1976, childhood friends Sumner and Hook separately attended a Sex Pistols show at the Manchester Lesser Free Trade Hall. The following day Hook borrowed £35 from his mother to buy his first bass guitar. Sumner later said that he felt that the Pistols "destroyed the myth of being a pop star, of a musician being some kind of god that you had to worship". Inspired by the performance, Sumner and Hook formed a band with their friend Terry Mason, who had also attended the show. Sumner bought a guitar, and Mason a drum kit. They invited schoolfriend Martin Gresty to join as vocalist, but he turned them down after getting a job at a local factory. An advertisement was placed in the Virgin Records shop in Manchester for a vocalist. Ian Curtis, who knew them from earlier gigs, responded and was hired without audition. Sumner said that he "knew he was all right to get on with and that's what we based the whole group on. If we liked someone, they were in".
Buzzcocks manager Richard Boon and frontman Pete Shelley have both been credited with suggesting the band name "Stiff Kittens", but settled on "Warsaw" shortly before their first gig, referencing David Bowie's song "Warszawa". Warsaw debuted on 29 May 1977 at the Electric Circus, supporting the Buzzcocks, Penetration and John Cooper Clarke. They received immediate national exposure due to reviews of the gig in the NME by Paul Morley and in Sounds by Ian Wood. Tony Tabac played drums that night after joining the band two days earlier. Mason was soon made the band's manager and Tabac was replaced on drums in June 1977 by Steve Brotherdale, who also played in the punk band Panik. During his tenure with Warsaw, Brotherdale tried to get Curtis to leave the band and join Panik and even got Curtis to audition for the band. In July 1977, Warsaw recorded a set of five demo tracks at Pennine Sound Studios, Oldham. Uneasy with Brotherdale's aggressive personality, the band fired him soon after the demo sessions. Driving home from the studio, they pulled over and asked Brotherdale to check on a flat tyre; when he got out of the car, they sped off.