Krokus started life in 1974 playing symphonic Rock similar to Genesis, Emerson Lake and Palmer and Yes. After four years, and two not-so-well received albums, Krokus (1975) and To You All (1977), featuring Henry Friez (vocals), Chris Von Rohr (bass/vocals), Fernando Von Arb (guitar/bass), Juerg Naegelli (keyboards/vocals), Tommy Kiefer (guitar/vocals) and Freddy Steady (drums) they switched to a more AC/DC style for the Painkiller (1978) release. Their music consisted largely of basic formulas of simple riffs and repeated lyrics. Von Rohr took over vocals when Friez left but his vocals lacked the range needed for their new style, so he stepped down to take the bass spot, with Maltezer Marc (Real Name: Marc Storace; ex-Tea) replacing him. Naegelli occasionally played keyboards and would eventually take over the technical side of the band's operations after the forthcoming Hardware album. Pay It In Metal (1979) didn't offer much but more attempts at their new style.
Metal Rendezvous (1980) fell right in line with the resurgence of British Heavy Metal by being heavier then any of their past works; it proved to be a turning point for the band. The following two follow-up albums, Hardware (1981) and One Vice At A Time (1982), followed the same path, but were slightly more radio friendly, making 44 and 28 respectively in the U.K. charts. Membership changes were in the works: Mark Kohler, an ex-roadie, took over from Kiefer, while Steve Pace took over on drums. Kiefer wouldn't be gone long and came back to replace Rohr.
The Headhunter (1983) release made it to Billboard 25 with its fast paced and high speed feel; it also broke well in the U.K. charts making it their most successful. During the tour the line-up featured Von Arb, Storace, Klavin plus Andy Tamas (ex-Black Oak Arkansas; replaced Koehler on bass when he reverted to guitar). After the release, more line-up changes commenced, with the temporary addition of Tommy Kessler on bass (taking over from Tamas) and Steve Pace to replace Steady, and the exit of Pace again for Jeff Klaven. These changes delayed the release ofThe Blitz (1984), which made it to U.S. 31, but mostly due to the efforts of its predecessors and not so much on their cover track of Sweet's Ballroom Blitz, despite it being the best track offered. Change Of Address (1985) came and went without notice. It's only newsworthy event being Tommy Kessler leaving the bass spot when Van Rohr returned, as did Alive And Screamin' (1986).
In 1986 Kiefer committed suicide and their fortunes went downhill from there. Several more membership changes plagued the Heart Attack (1987; including the drum position now being occupied by Dani Crivelli and Mark Kohler returning on guitar), the "best of..." compilation Stayed Awake All Night (82-86) (1989), and Stampede (1991) albums including Manny Maurer replacing Von Arb on guitar and Peter Tanner replacing Storace on vocals (who would subsequently return after the Stampede album). The line-up changes were so much so that by 1990 most of the operation had been completely replaced several times over. More membership changes came shortly later with Peter Haas assuming the drums and Carl Sentence on vocals. They were thought dead, but after the "best of..." The Dirty Dozen (80-83) (1993) a set of new albums, To Rock Or Not To Be (1995) and Round 13 (1999) came shortly later with the best of compilation The Definitive Collection (2000) and Rock The Block (2003) following up the rear.