Onslaught are a British thrash metal band, formed in 1983 by guitarist Nige Rockett and drummer Steve Grice. Joined by Jase Pope and Paul Hill on vocals and bass respectively, the band initially drew influence from the second wave of Punk bands such as Discharge and The Exploited. A demo was recorded by this line up.

Jase Pope and Paul Hill were soon to be replaced by Roge Davies and Paul Davies and the subsequent line-up recorded single "What Lies Ahead."

In 1984, Paul Mahoney and Jase Stallard joined to replace Roge Davies and Paul Davies. The band started to write more Heavy Metal songs than their original punk sound. This was mainly influenced by the early releases of Thrash Metal bands. The output of this was the 1985 release of Power from Hell on the Children of the Revolution record label.

Late 1985 saw the introduction of Sy Keeler to the band who took over the vocals duty from Paul Mahoney. Mahoney retained his place in the band but took over playing bass from Jase Stallard, who in turn took on the role of rhythm guitarist - giving the band a second guitarist. During the early months of 1986, they set out to record their second album at a recording studio in London. The Force was released in the spring of that year through the Under one Flag record label. Paul Mahoney, citing personal reasons, quit the band and was replaced by James Hinder.

1987 saw a change in the policy of the sacking of band members; Jase Stallard's guitar playing came into question and the band dismissed him and found a replacement in Rob Trotman. Using this line up, they set out to write material for a third album. Having drawn the attention of London Records, the label signed the band. Mid 1988 the band began to start recording In Search of Sanity. Upon hearing the album, the record label felt that a more versatile vocalists was needed to do the music more justice. Although the band felt that Sy Keeler's vocals on the demo recording had the right sound, the production had a more polished sound - hence the need for a more polished vocalist. Steve Grimmett, formerly of Grim Reaper, was drafted in to replace the departing Sy Keeler. Owing to this development, the release of the album was delayed until the summer of 1989.

In early 1990, Steve Grimmett decided to leave the band under personal reasons and was replaced by Tony O'Hora. The band then set out to write and then record their fourth album. London Records decided not to renew their contract with Onslaught, leaving the band without a record deal. Although the band tried to secure a deal, nothing came to light and they decided to fold in early 1991.

2004 saw the band reform with the line up of Sy Keeler, Nige Rockett, James Hinder and Steve Grice. The second guitarist was Welshman Alan Jordan, formerly of Mirror Mirror. Amidst the touring, writing for the fourth album began and in early 2007 saw the release of Killing Peace.