Castrum was formed in September of 1994, when buddies Cornelius (guitar) and Georgius (vocals) decided to create a unique Death Metal band. At the beginning they characterized the style of Castrum as Gothic-Brutal Death Metal with medieval parts. The band started with drummer Lancelot, but after four months Lancelot left the band for military service draft, leaving them without a drummer for a time until September of 1995 when new drummer Werkoff joined the band and the line-up of Castrum became stable. In February 1996 their first demo emerged, the 7 song Burial Of The Affection. In June 1996 they began recording of their first studio demo called Flames By Impiety, including 2 tracks and intro/outro of Medieval Death Metal and was produced by Cornelius personally.
In October 1996, the band recorded three new songs for the second studio demo Pleasure In The Deeds Of Horror, produced by Eugene Petrus and Cornelius. Well received by the underground press and fans worldwide, the lyrical conception of Castrum mostly dealt with historical events but there were some lyrics based on the band members' personal experiences. Werkoff experienced family issues and so was the next to leave and replaced with drummer Doni (ex-Souldrest).
10th of October 1998 would be their next big break when Castrum was invited to Banska Bystrica (Slovakia), where they played with bands like Krabathor, Aggressive Tyrants, and Sanatorium. After this show, however, Sharapoff would leave and a new bassist Roman was hastily recruited in time for the band to sign a deal with Ukrainian based Metal Force Records' to see their MC release The Leading Spirit Of Medieval Tortures containing a collection of almost all the early materials of Castrum in 55 minutes. The debut CD album "Hatenourisher" (2001) on Canadian Bloodbucket Productions', as well as in MC format on Metal Force Records'.
During January 2002 the band finished the recordings of their 2nd album, titled as Mysterious Yet Unwearied (2002) on Bloodbucket Productions'.