Initially founded by guitarist Sasrof and drummer Throne, Sundsvall based IMPERIAL issued an inaugural demo in 1994 entitled 'Mori Voluntaria' with session vocals courtesy of Blackblood. Throne decamped and new blood drummer Amath and bassist Gorgorium were enrolled for a 1996 session 'The Imperial Darkness' with guitarist Thyrfing. IMPERIAL's line-up problems were exacerbated when Amath quit. Session drums were supplied by Lord Mysteriis of SETHERIAL as Blackblood returned to take over the lead vocal position permanently for the third demo 'De Fördömdos Legion', recorded at Court House Studios and distributed by Arte De Occulta Productions. 'Darkness Enshroud' followed that October.

IMPERIAL was put on ice whilst various members tried their hand at a new act HELVETE with Lord Mysteriis and his SETHERIAL colleague Kraath. By 1999 this outfit became DIABOLICUM with the addition of guitarist Nathzion.

DIABOLICUM bowed in signing to the Napalm label for the 1999 opus 'The Grandeur Of Hell'.