[2] The initial lineup consisted of Mikael Åkerfeldt (Opeth) on vocals, Dan Swanö (Edge of Sanity, Nightingale) on drums, Anders "Blakkheim" Nyström (Katatonia, Diabolical Masquerade) on guitar, and Jonas Renkse (Katatonia, October Tide) on bass.

[3][4] In 2004, Åkerfeldt left Bloodbath, wanting to free up more time for his primary band Opeth, with Peter Tägtgren (Hypocrisy) being brought in to replace him.

The lineup changed further, with Swanö switching to guitar and Martin Axenrot (Witchery, Satanic Slaughter, Opeth) filling the position of drummer.

With these changes the size and subsequent scope of the band increased, expanding beyond that of what was initially only a secondary side project.

That same year, Åkerfeldt rejoined for a single live show at Germany's Wacken Open Air on 5 August.

[7] On 30 January 2008, it was announced via the Bloodbath website that Åkerfeldt would be rejoining the line-up on vocals, along with new member Per Eriksson (ex-21 Lucifers, ex-Genocrush Ferox) on guitar.

[12] Guitarist Anders "Blakkheim" Nyström explained the band's composition process: "There has always been a lot of spontaneity with Bloodbath.