As early as 2009, Testament commenced writing new material for their tenth album. In an interview with Metalheadz, guitarist Eric Peterson stated that there were about four songs written and that "there's other guys in the band who like to play the more rock melodic style but the next one is gonna be a bit heavier." In a January 2011 interview during the 70000 Tons of Metal cruise, frontman Chuck Billy revealed that Testament had been working on six new songs, with four or five "maybe left to write," and would begin recording their new album by early March. On 18 May 2011, guitarist Alex Skolnick posted an update on his Twitter, saying, "Another tune done! My riffs from last week [plus] some of [fellow Testament guitarist Eric Peterson's plus] new ones we wrote today. Planning one more, then we've got more than we need."  Testament began recording their tenth studio album on June 20, 2011. Drummer Paul Bostaph was unable to take part in the recording due to a "serious injury", although 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. It was also reported that Lamb of God drummer Chris Adler would make a special guest appearance on a couple of bonus tracks.  Testament appeared at the California dates of the summer 2011 Rockstar Energy Drink Mayhem Festival, replacing In Flames.  On 14 July 2011, it was announced that the tenth Testament studio album would be called Dark Roots of Earth, which, after many delays, was released on July 27, 2012. Dark Roots of Earth debuted at No. 12 on Billboard 200, the band's highest chart position to date. Prior to the album's release, the band toured in the fall of 2011 with Anthrax and Death Angel. Overkill was invited to the tour, but due to the pre-production of their sixteenth studio album The Electric Age, they did not participate. It was announced on 1 December 2011 that Paul Bostaph had left Testament. Gene Hoglan recorded the drum tracks for Dark Roots of Earth and continues to play live with the band. In interviews, Testament have expressed pleasure in Hoglan's playing, and hope that he would continue playing with the band for the foreseeable future.

Answer this question "What was the name of their band" by extracting the answer from the text above.
Testament