Decimus Furius was born in Rome. After his father was forced to commit suicide for his philosophic ideas, his mother soon committed suicide as well, leaving Decimus homeless on the streets. In 281 A.D., upon starving to death, Decimus' mutant powers emerged. He was consequently attacked and killed dozens of humans before being imprisoned. After years of imprisonment, he was sent to the Colosseum as a gladiator and battled everyday for the next few years of his life for his survival and eventual freedom, and became worshiped as being the dark god Minotaur.
Decimus was watched by the eternal mutant Apocalypse and selected as his Final Horseman War in the event that all other plans of Apocalypse failed. He first fought Deadpool, and later the rest of X-Force as well.
Clan Akkaba activated him to serve as a Horseman to a young clone of Apocalypse. Psylocke described its mind as "a hollow room encompassed by shadow, echoing an unquenchable lust to conquer." During a raid on a Clan Akkaba stronghold, Fantomex was able to defeat him by misdirecting War's feelings so that he thought he was in love with Psylocke. He subsequently exploded, but was fully regenerated a few instants later.
However, he still remained in love with Psylocke, taking days to collect himself mentally. When X-Force attempted to assault Clan Akkaba's lunar base, he took E.V.A. down and, along the other Horsemen, defeated them. He brought her back to his chambers and confessed his feelings. Now that his mind wasn't filled with sorrow and hate, Psylocke was able to use her telepathy to escape and find the cloned Apocalypse.
Dark Angel Saga
The Horsemen soon followed over to Archangel's side, with War included. He fought Psylocke again, and this time apparently had no feelings for her. Unfortunately, she had none for him as she fought mercilessly. War later possessed Deathlok and brought him over to his side, and kept him over until Deathlok finally broke free of it and War escaped.
Furius and his fellow Horsemen accompanied Apocalypse's son Genocide aboard the Starcore Station to use its broadcast magnification chamber to send a message to the Celestials Apocalypse once served. A Celestial Gardener appeared to give Genocide a Death Seed, but suddenly, the Apocalypse Twins interrupted the ceremony. Furius and Horseman of Famine Jeb Lee confronted the twin Eimin, but both were swiftly killed by Eimin's chronokinetic acid.
Decimius Furius was a mutant with numerous abilities:
- Superhuman strength and durability
- War-filled Psyche: Attempts to read his mind can backfire, resulting in the reader being overcome by War's sorrow and hate.
- Empathic War Infection: A successful strike with his axe will infect his victim with the cold thirst for war, causing that victim to attack those around him.
- Regeneration: He was able to piece himself back together after exploding.
He was proved unable to resist to his own feelings of love, making him explode.
Wields a four-bladed axe.