One of the first Thrash acts to come out of California after Metallica, Testament first strummed their guitars as Legacy in 1983 and changed their name two years later. The original line-up featured Steve Souza (vocals), Alex Skolnick (guitar; replacing pre-Testament guitarist Derrick Ramirez), Eric Peterson (guitar; cousin to Derrick Ramirez), Greg Christian (bass) and Louie Clemente (drums). Souza, however, didn't stick around long, and soon left for Exodus to be replaced by Chuck Billy.
Their introduction as Testament was the ferocious The Legacy (1987), which firmly set them up as contenders in the Thrash arena, and a strong act of the so-called "Bay-Area Thrashers", a group of early Thrash purveyors which included the membership of Heathen, Defiance, Vio-Lence, Death Heathen, Forbidden, Death Angel, Slayer, Anthrax and Metallica, amongst others. Following their live EP, featuring them at Holland's Dynamo Festival titled Live At Eindhoven (1988), The New Order (1988) was released featuring improved songwriting, as well as the classic track, Disciples Of The Watch. The record consolidated their popularity. Skolnick, however, had become bored with the pure Thrash concept, for sometime he had been moonlighting in Stuart Hamm's touring band. A creative compromise was met when this influence was incorporated in Practice What You Preach (1989). This album featured a more melodic Power Metal sound and a more approachable feeling that got them a U.K. top 40, their second U.K. charting, and first U.S. charting at 77. Souls Of Black (1990), however, was a rushed deal intended to be released in time for the Clash Of The Titans European tour with Megadeth, Slayer and Suicidal Tendencies. Although it was a well-intentioned marketing plan, the album suffered in every other way because of it.
Skolnick finally had enough and departed to joinSavatage; Clemente left also after the follow-up, The Ritual (1992), to be replaced by Glen Alvelais (ex-Forbidden; guitar) and Paul Bostaph (ex-Forbidden; drums) in time for the release of the Return To The Apocalyptic EP in 1993. Bostaph, however, would soon depart to join Slayer with John Tempesta (ex-Exodus; drums) joining on permanent. Alvelais didn't stick around long either, and quickly left after the support tour in favor of James Murphy (ex-Death/ex-Obituary/ex-Cancer/ex-Discarnate/ex-Konkra/ex-Agent Steel).
Low (1994) saw them return to their full blast Thrash style of old, with an attempt at Death Metal in the track Dog Faced Gods.
Live At The Fillmore (1995) would see them on a live recording, and see Jon Dette (ex-Evildead) join on drums to replace the departing Tempesta, who had left to join White Zombie. The album also proved to be their first on their own label, 'Burnt Offerings', since 'Atlantic' had dropped them. Jon Dette left to replace Bostaph in Slayer, so Chris Kontos (ex-Machine Head) took over his spot. The seventh studio album had barely gotten to pre-production stages when it was decided that Testament was no longer a viable property and left.
It wasn't long, however, before they reformed under the line-up of Chuck Billy (vocals), Gene Hoglan (ex-Death Angel/ex-Death; drums), Glen Alvelais (guitar), Eric Peterson (guitar) and Derrick Ramírez (bass). Demonic would finally see the light in 1997. Signs Of Chaos - The Best Of Testament (1998) would be a compilation of their works and followed shortly later.
Hoglan now left to join Strapping Young Lad and was replaced by the returning Dette. But Dette wouldn't stick around long for a permanent replacement was found in D ave Lombardo (ex-Slayer/ex-Grip Inc.). At this time, however, more membership changes were underway with Alvelais and Ramirez leaving and being replaced with the returning Murphy and the newly founded Steve DiGiorgio respectively, culminating in the The Gathering (1998) release. But after the support tour in the U.S.A., Lombardo and Murphy left the band, and were replaced by ex-Forbidden drummer Steve Jacobs and ex-Vicious Rumors guitarist Steve Smythe respectively.
Lead guitarist James Murphy was, soon after, diagnosed with a brain tumor. Through various fundraisers, he raised the money to afford surgery and eventually made a full recovery, but was unable to recall anything from the recording of The Gathering. In 2001, Chuck Billy was diagnosed with germ cell seminoma, a rare form of testicular cancer, but it only affected his lungs and heart; his cancer was also treated successfully.
Eric Peterson formed a Black Metal side project called Dragonloard, involving most of the other band members. In 2001 he released First Strike Still Deadly.
By 2003 Chuck Billy had completely recovered, and the band began performing live again with a new drummer, Jon Allen of Sadus. In 2004, the band changed their lineup once again for their summer festival appearances. Jon Allen was replaced by Paul Bostaph, returning to the band for a second stint after a decade's absence. Lead guitarist Steve Smyth departed to join Nevermore and was replaced by ex-Halford guitarist "Metal" Mike Chlasciak. Shortly after Steve Smyth's departure, Eric Peterson fell down a flight of stairs, breaking his leg, and was unavailable for some dates; he was temporarily replaced by Steve Smyth.
The act released their first studio album in nine years, The Formation of Damnation (2008), through 'Nuclear Blast Records'. It is the first Testament album to feature Alex Skolnick on guitar since 1992's The Ritual, and the first to feature bassist Greg Christian since 1994's Low.
In late September 2008, it was announced that Testament would perform at the "Priest Feast European tour with headliners Judas Priest and Megadeth in February and March 2009.
Testament began recording their new album on June 20, 2011. Paul Bostaph was unable to take part in the recording due to a "serious injury", however he was expected to rejoin when the band tours to support the album. Gene Hoglan, who played drums on the band's 1997 album Demonic, filled in for Bostaph.
Dark Roots of Earth (2012) debuted at 12 on Billboard 200, the band's highest chart position to date.
In January 2014, bassist Greg Christian left again. Steve DiGiorgio returned to the band as his replacement and would be involved in the making of the band's next album, The Brotherhood of the Snake that was released in 2016.