A punishing thrash unit based out of Bristol, England, Onslaught initially started out as a second wave hardcore punk act in the vein of Exploited and Discharge before tightening things up and riding the speed metal and thrash wave of the 1980s alongside contemporaries like Slayer, Exodus, and Testament. The group issued a pair of notable, top-tier thrash albums in 1985 and 1986 before adopting a more traditional heavy metal sound for their third outing. They disbanded in 1991, but returned to both the stage and the studio in 2007, with their thrash cards renewed.

Onslaught was put together by guitarist Nige Rockett and drummer Steve Grice in 1982. The two musicians were working to forge an ultra-aggressive speed metal sound that was becoming more and more popular in the days of early Slayer and Metallica. In 1985, the duo were joined by bass player Jase Stallard and vocalist Paul Mahoney. The quartet quickly worked up enough material for a record, and later that year, the debut Power from Hell was recorded and released on U.K. independent record label Cor. A forceful and raw-sounding effort, 1985's Power from Hell, along with Slayer's Hell Awaits, were among the better speed metal offerings of the year. The band's 1986 follow-up, The Force, was an even stronger effort released originally on the much larger Music for Nations imprint Under One Flag. In a bit of an odd lineup change, Stallard switched instrumental duties by becoming the group's second guitarist, and new vocalist Sy Keeler replaced Mahoney, who took over Stallard's vacated bass duties. A more competent recording, The Force sounded better than the group's debut and maintained many of the Slayer-like thrash sensibilities. New bassist James Hinder replaced Mahoney when the ex-singer was finally demoted out of the ranks of Onslaught.

As a serious following for the band began to emerge, they were eventually signed to Polydor imprint London Records. After recruiting former Grim Reaper vocalist Steve Grimmett and guitarist Rob Trotman (replacing Stallard) into the band, the first major-label effort for Onslaught, In Search of Sanity, was released on London in 1989. While their previous recordings sported an extremely hard edge and an almost death metal stance, In Search of Sanity moved the group's sound into more familiar trad-metal territory. Perhaps due to the huge delay between releases, and the curious move toward a relatively mainstream musical approach, In Search of Sanity was a critical and commercial failure for the thrash veterans. Grimmett left the group in 1990 to form Lionsheart, and Tony O'Hora signed on as vocalist for Onslaught, but London Records decided not to renew their contract, leading to the group deciding to call it quits the following year.

Onslaught re-formed in 2005 around a lineup consisting of Steve Grice, Sy Keeler, Nige Rockett, James Hinder, and Welsh guitarist Alan Jordan. Hinder left the band the following year, but not before appearing on their long-awaited fourth LP, 2007's Killing Peace, which marked a return to the hard-hitting thrash attack of Power from Hell and The Force. The group moved to Germany's AFM Records for their next full-length, the mosh pit-inducing Sounds of Violence, and in 2013 they released the aptly named VI, which featured a retooled lineup made up of Keeler, Rockett, Andy Rosser-Davies, Michael Hourihan, and Jeff Williams. In 2018, the band issued the concert LP/DVD Live at the Slaughterhouse.

The following year, Onslaught released the single "A Perfect Day to Die," which paid tribute to the classic Motörhead lineup, while also starting work on their seventh studio album. At the beginning of 2020, the group parted ways with original vocalist Keeler, who was replaced by Dave Garnett. More lineup changes followed with James Perry and Wayne Dorman providing drums and guitar, respectively. The refreshed band headed to Dugout Studios in Uppsala, Sweden, with Daniel Bergstrand (Meshuggah, In Flames) to record. The resulting album, Generation Antichrist -- which also featured a re-recorded version of the Motörhead tribute single, this time with Garnett on vocals -- was issued toward the end of 2020. In Search of Sanity-era vocalist Steve Grimmett died on August 15, 2022 at the age of 62. ~ Vincent Jeffries, Rovi