Testament became a band back in 1984 under the name legacy. They soon after changed their name to Testament because an older band had chosen the name legacy and Testament didn't have any money to buy the rights to the name. The line up at this time consisted of Chuck Billy, Eric Peterson, Greg Christian, Louie Clemente, and Alex Skolnick. They recorded 4 succesful albums with this line up, but then Louie and Alex had some creative differences with the band and split. They wanted to make a more commercial radion/mtv friendly album.
After this, Testament got guitarist James Murphy and drummer John Tempesta to join the group. Together they recorded the album "LOW" but after this John Tempesta left to join White Zombie. Soon after Testament left their record company "Atlantic" because they weren't promoting them, and wanted testament to record an alternative album. They also got drummer Jon Dette to fill in John Tempesta's shoes. The next album made was Live At The Fillmore, on their own record label "Burnt Offerings." Greg, Jon and James left the band after this album for their own personal differences. Chuck and Billy then got Chris Kontos of Machine in the band. He wanted to change the band's name to "dog faced gods" and start over, but this didn't work out, and the band officially broke up in 1996.
The Chuck and Eric got back together and started writing new material then got people in the band again and Testament was formed again. They went through a few more changes in the lin up, but at the release of 1999's the gathering, the line up was Chuck Billy, Eric Peterson, Dave Lombardo, Steve Digiorgio, and James Murphy.