In December of 1994, Sasrof and Thorne joined forces to form Imperial. The first demo appeared under the title "Mori Voluntaria". The tape was recorded in two days at a mental hospital and included the session vocals of Blackblood. Following Thorne's departure, drummer Amath and bass player Gorgorium joined the line-up. In 1996 the second demo "The Imperial Darkness" was released. Vocals and lead guitar on this recording were handled by Thyrfing. Amath left the band and Mysteriis of Setherial joined as a session drummer. The third demo "De FÆrdÆmdas Legion" was released by Arte De Occulta shortly thereafter. In 1997, the members of Imperial formed the black metal band Helvete together with Mysteriis and Kraath of Setherial. The project was put on hold when Sasrof took over the bass responsibilities for Setherial. In 1999 Imperial changed their name to DiabolicuM, Nathzion joined the ranks as lead guitarist and DiabolicuM's debut (the Grandeur Of Hell – Napalm records 1999) was recorded at Greencastle studios Records in October of the same year. In the summer of the year of 2000 DiabolicuM left Napalm to explore new worlds, and signed a deal with the Italian label Code666. The new album “The Dark Blood Rising” was released in 2001 and it is now considered a classic in the Industrial Black Metal scene thanks to the perfect mix of Swedish Black Metal and Industrial-Ambient-Noise. In the following years the band published a colllection of the early demos (Killing spree 1.5) and a couple of split 7“ EP with Watain and Angst, then started working on the third album with new vocalist Niklas Kvarforth (Shining) and lead guitarist Likstrand. After several setbacks and delays, they are finally able to present „Ia Pazuzu (The Abyss of the Shadows)“, a new milestone in the Industrial Black Metal scene.

In the summer of the year of 2000 Diabolicum left Napalm to explore new worlds and signed a deal with the Italian label Code666 and the in the May of 2001 the second album The Dark Blood Rising (The hatecrowned retaliation) was unchained.

A long waiting for the following album, "Ia Pazuzu", released in 2015.