Formation; classic line-up (1977–1979)
Discharge was formed in 1977 in Stoke-on-Trent by Terence "Tez" Roberts (vocals) and Royston "Rainy" Wainwright (guitar). They soon recruited Roberts's younger brother Anthony "Bones" Roberts on lead guitar, Nigel Bamford on bass and Anthony "Akko" Axon (Allmusic gives the alternate nickname "Hacko"  ) on drums. The musical style of the band was initially influenced by 1977-era punk bands such as the Sex Pistols, The Damned and The Clash. Engaging Tanya Rich as their manager, the band recorded their first demo, supported bands such as The Ruts, The Clash and The Damned at The Victoria Hall, Hanley, and began touring.
Axon left later that year, followed by Bamford, and the band recruited their roadie Kelvin "Cal" Morris as vocalist, moving Terry Roberts to drums and Wainwright to bass. With Morris's addition, the group abandoned their previous Sex Pistols-influenced material and developed a new set of songs with a retooled sound. Anthony Roberts played guitar with a heavy, distorted, and grinding style and Morris shouted or screamed vocals without melody. The bassist played with a "immense gurgling over-driven" bass tone. The tempo of the band's songs also steadily increased over the next year or so. The stylistic transition made by the band was part of a broader trend in the early 1980s in the UK, which is known as "UK 82" or second generation UK punk. Discharge and bands such as Chaos UK, Amebix, and Charged GBH took the existing 1977-era punk sound and melded it with the incessant, heavy drumbeats and "wall of sound" distortion guitar pioneered in the Overkill album by Motörhead.
The new, harder-edged style also tended to use much darker, more nihilistic and violent lyrics, focusing on anarchist and pacifist themes while emphasizing the grisly effects of nuclear warfare and the social ills caused by capitalism. Like Crass, Discharge supported anarchism and displayed the anarchist symbol. The band also expressed its political and social themes in its albums' artwork, which depicted the horrors of war using an iconic black-and-white photography style. One of the notable images is the "Impaled Dove" artwork from a 1930s John Heartfield anti-war poster, which depicts a dove impaled on a bayonet. The first gig with this new line-up and new sound was at Northwood Parish Hall. Among the audience was local record shop owner Mike Stone, who ran the Clay Records punk record label.
Early EPs; Hear Nothing See Nothing Say Nothing (1980–1982)
In 1980, Discharge signed with Clay Records, and recorded their first single Realities of War in February 1980, which made the UK Indie Chart when it was released in April, after being played on BBC1 DJ John Peel's show, peaking at number 5 and spending 44 weeks in the chart. The band also performed their first shows outside of Stoke-on-Trent in 1980, playing in Leicester, Preston and Glasgow. After two further EP releases in that same year, founding member Terry Roberts departed, later joining UK Subs, to be replaced initially by Keith Haynes of Picture Frame Seduction and soon thereafter by Dave "Bambi" Ellesmere (formerly of The Insane) before the Why? EP was recorded. Ellesmere did not stay long, and the band replaced him with Garry Maloney of The Varukers on drums. Why? gave the band their first UK indie number one. Why? had cover photos showing the corpses of dead civilians. The song "Visions of War" had an "unrepentantly angry and punishing attack" and it became a signature song for the group. The songs "Maimed and Slaughtered," "Does This System Work?" and "Mania for Conquest" set out the song and sound template for crust bands. At the same time, the record showed that it was possible for a hardcore band to incorporate the sonic power of "heavy metal without sacrificing ideology or anger".
Discharge "...developed a brutal, extremist approach to punk that would give rise to thrash."  A reviewer from Punknews.org calls the music from this period "ugly and jagged without the artistic convolution of their no-wave contemporaries overseas", composed of "catchy, repetitive, stomping chords[,]...drumming that seems to emphasize creating a hellacious racket rather than keep a steady beat" and "very serious and socially conscious" song lyrics. The reviewer notes that "instead of creating a melody, vocalist Cal’s grunting shout...blends in with the rhythm", in effect becoming "a fourth [rhythm] instrument". Cal's lyrics and singing were "...short bursts of brutal sloganeering that made no concessions to melody or meter." Cal's deep "growl anticipated...[the] vocals that death metal and grindcore later" used. "Cal’s hoarse barking" sounded angry, and his anarchist lyrics "against government oppression and nuclear war, were like nihilist haikus, delivered without metaphor, nuance, or humour."
The band's songs were "played at warp speed, accompanied by a rumbling bass and a merciless, galloping drumbeat", with songs usually under two minutes and done at a fast tempo.
The Punknews.org reviewer argues that the early 1981 EP Why? "...revolutionized everything...[paving the] way for the atonal shredding of hardcore punk, thrash, death metal, and grind, but also the dead-serious political ideals and brutal backing of crust hardcore". Ian Glasper described the EP as "one of the most potent anti-war records ever made". Tom G. Warrior of Celtic Frost credited Discharge as "a revolution, much like Venom", saying, "When I heard the first two Discharge records, I was blown away. I was just starting to play an instrument and I had no idea you could go so far. And to me, they were unlike other punk bands--they sounded more like metal."
Discharge recorded their first album, 1982's Hear Nothing See Nothing Say Nothing, which was the number one punk album of all time in a poll by Terrorizer magazine. In David Konow's history of heavy metal, he calls the album the band's "...crowning achievement, a mercilessly brutal masterpiece."  The album reached number two on the indie album chart and number 40 in the UK Album Chart. In the early 1980s, "[i]conic punk fanzines like Flipside, which could make or break [band] reputations, pronounced them [Discharge] "fucking great." 
Treble zine called it one of the top ten essential hardcore albums, along with Black Flag's Damaged and the Dead Kennedys Fresh Fruit for Rotting Vegetables. Treble zine states that the music on HNSNSN was "much, much heavier" than previous punk and states that it influenced "punk rock, [and]... metal circles" with its "raw and intense" sound. Anthrax guitarist Scott Ian stated in 2015 that "You put on... Hear Nothing, See Nothing, Say Nothing album now, and it’s still as heavy and brutal as anything out there."
The group played regularly throughout the UK, often appearing with bands such as GBH and The Exploited, and the success of the debut album also saw them touring Canada, the United States, Italy, Yugoslavia, Holland, Finland, and Sweden. The band had trouble getting into Canada at the border crossing at Buffalo, New York, as border guards thought the band looked like "animals". The lyrics on the album tended to be short political statements that were repeated. The album's title track, for example, consists of only three lines:"Lied to, threatened, cheated and deceived/ Hear nothing, see nothing, say nothing/ Led up garden paths and into blind alleys." The song "Free Speech for the Dumb" is even more lyrically stripped down; it consists solely of the words from the title repeated emphatically.
1982's "State Violence State Control"/"Dooms'day" single garnered further critical praise, described in the fanzine Love and Molotov Cocktails as "...just about the most perfect realisation of a combination of the musical power of Motörhead and the lyrical mastery of Dead Kennedys at their best. Discharge are out there on their own, at the top of their game and it's hard to see how they can improve on this."
Heavy metal crossover period; first breakup (1982–1987)
In 1982, Anthony Roberts left the group, later to form Broken Bones with his brother Tezz joining him. He was replaced by Peter "Pooch" Purtill (Allmusic and Glasper give the alternate spelling "Pyrtle" for his last name) who brought significant heavy metal influences. Purtill used a rock and metal style of guitar playing, including rock-oriented guitar solos. The Warning... EP shows drastic stylistic differences, with Morris changing his angry shouts to a mix of regular singing and . Morris began to use a heavy metal, Ozzy Osbourne-influenced vocal style. As well, the band used significantly slower tempos and their D-beat punk style was replaced with metal-oriented beats.
With the release of Ignorance, Purtill and Maloney left the band to form the punk/metal crossover band HellsBelles, to be replaced by guitarists Les "The Mole" Hunt and drummer Michael "Micky" Gibson. Following the later addition of second guitarist Stephen "Fish" Brooks, they released 1986's Grave New World, a mainstream metal album with a glam sound from Morris's high-pitched singing style. The album reached the indie top 10, but the band struggled with personnel problems as Morris departed and was briefly replaced by ex-Wrathchild frontman Rob "Rocky Shades" Berkeley the following year. The group disbanded shortly thereafter.
Reformation with new line-up (1990–1999)
Morris formed a new version of the band in 1990 with Andrew "Andy" Green on guitar, Anthony Morgan on bass, and Mika Karppinen initially playing drums, only to be replaced by the returning Maloney. The Live At The City Garden, New Jersey album on Clay Records followed. In 1991 they released Massacre Divine, which retained the metal sound, though with a noticeably harder edge than on Grave New World. Morris again changed his vocal style, this time to rougher growling, similar to Brian Johnson of AC/DC. They toured widely in support of the record, including their only visit to Japan, but the tour was negatively received. In 1993 they released Shootin' Up the World, which continued Cal's new vocal style, but the songs were significantly heavier than on Massacre Divine. The album retains the metal direction, although experiments with strange lyrics and song structures, coming close to thrash metal at times. Morris assembled further versions of the group, but they again disbanded in 1999.
Reunion of classic line-up and End of Days (2001–present)
Discharge performing in Rome in 2006. The distinctive lettering of the band's name can be seen in the banner at the back of the stage.
In 2001, the classic line-up of Morris, Roberts, and Wainright reunited after meeting at a party held by original bassist Bamford, and in 2002 they released their self-titled album Discharge, a return to their early 1980s style featuring political commentary and aggressive playing. As well, they brought back their intense D-beat drumming style, although combined with the remaining metal influence, it gave the album a speed metal influence with its thrashy riffs.
Morris would not commit to touring to promote the album and left the band, to be replaced by Anthony "Rat" Martin of The Varukers. The single "The Beginning of the End" was released in 2006, which marked a further step towards a return to the punk sound. Dave "Proper" Caution replaced Terence Roberts after his second departure this same year, and the group released the Disensitise album in 2008. In 2011 the band released an EP titled "Propaganda Feeds". In 2012 they released a split single with American band Off with Their Heads, released on Drunken Sailor Records. In 2014, they played the Black and Blue Bowl in Brooklyn, New York. Rat was replaced by Jeff "JJ" Janiak, while Tezz Roberts returned to the band, except this time on rhythm guitar rather than drums making Discharge a five-piece.
On 3 June 2015, the group premiered a new song called "New World Order". An EP containing the song and a live recording of "Ain't No Feeble Bastard" was released on 16 January 2016, entitled New World Order. On 10 February 2016, the band announced their 7th studio album, entitled End of Days, was to be released sometime in April. It will be Discharge's first album with singer JJ and the first album as a five-piece band. On 3 March 2016, the Nuclear Blast YouTube channel uploaded a new song on and later on through streaming services, entitled "Hatebomb." The same day, they released the track listing for End Of Days.
Discharge's seventh studio album, End of Days, was released on April 29 through Nuclear Blast Records and entered the Official UK rock charts at #10 and #23 on the indie charts. The success of the album saw the band touring Europe and the USA. MetalBlast gave the album a positive review, stating that it "...showcases everything about the band that has earned them their legendary status. The guitar work is fast and brutal, that famous d-beat drumming pattern is in full effect, and the vocals are a gruff, angry bark." The review states that the "songs are short, violent bursts of punk rock fury, brimming with an energy" with "a real sense of menace and sincerity in the tone" and it is "[r]elentless from start to finish". The production was praised as clear and "live"-sounding; the only negative comment was the lack of melody on the record.