A young veteran from the Vietnam War, Abraham Kieros was selected by Apocalypse to become the Horseman War. Paralyzed from the neck down and waiting to die in an iron lung, Apocalypse saw strength in War and restored his health in exchange for servitude. War willingly accepted, and became Apocalypse's most trusted of the Horsemen.
Despite Famine's disobedience, War often took charge of the situation, having experience in the battlefield while serving in the war. However, Death soon took over leadership, much to War's dismay. The Four Horsemen learned to ride as one, and attempted to lay waste to New York City. War actively took part in this, destroying several buildings with his mutant powers.
Confronted by Cyclops, who offered him a spot on the X-Men, War was able to get the best of him before he was teleported back to Apocalypse's ship. There, he battled Beast and Iceman, but was taken out after Iceman froze his hands. Apocalypse's mission a failure, he fled with War and Caliban.
The Horsemen regrouped much later, and War and Famine ambushed Colossus and Iceman, creating a diversion while Caliban kidnapped Cyclops and Jean Grey. War battled Colossus, who compared the Horseman to Mikhail Rasputin. Their mission a success, Famine and War fled, returning the two X-Men to Apocalypse, who was really Mister Sinister in disguise. War was eventually defeated by the other X-Men, who had come for their kidnapped companions.
Abandoned by Apocalypse, Abraham Kieros was forced to return to the hospital. Paralyzed once again, he was sought out by Archangel, who found him and healed Abraham of his wounds, and restoring the hope he had lost in people during the Vietnam War.