Redmond, Blutarch, and Gray Mann were born in 1822 as fraternal triplet sons of a wealthy Englishman, Zepheniah Mann, the owner of a successful arms manufacturing business. Gray, already sentient, intelligent and capable of fluent speech, was kidnapped by an eagle within minutes of birth during the Great Eagle Scourge of 1822 and goes missing for several years; Zepheniah would withhold knowledge of Gray from everyone else. Redmond and Blutarch were extremely competitive, attempting to vie for favor from their elderly father as to inherit the company after his death. In the 1860s, they convinced Zepheniah to purchase numerous pieces of land in the United States as assets for the company (under the mistaken belief that steam engines ran on gravel, and that the land was filled with it), but once they traveled there, they found the land to be barren dustbowls, with only the occasional gravel pit. Further, the travel caused Zepheniah to come down with numerous maladies, and died soon thereafter. In his will, Zepheniah bequeathed his munitions company, Mann Co., to his aide and tracker, the Australian hunter Barnabas Hale and his estate to his maidservant, Elizabeth. As punishment for their reckless and short-sighted scheme, Zepheniah's will ordered that Redmond and Blutarch were to share the worthless land they had made him acquire. Soon, Blutarch created his own company Builders League United (BLU) and hired mercenaries to take the land by force; Redmond followed suit with his own company, Reliable Excavative Demolition (RED).
Their battles continued for forty years, with neither brother relenting. Blutarch realized that they would die soon, and hired an engineer, Radigan Conagher, to build him a life-extending machine, believing that by outlasting his brother, he would inherit the land by default and win. Conagher was later met by a mysterious woman that offers him a stash of the valuable metal Australium in exchange for building Redmond an identical machine. Conagher agrees, but later it is shown that he also built a third identical machine for an unknown entity.
Battles between RED and BLU continued for over sixty years; both Redmond and Blutarch hired new mercenaries to fight for them in 1968. By that time, their battles are overseen by the Administrator, the granddaughter of Elizabeth, while the Australian Saxton Hale has become CEO of Mann Co, the company that provides all the weaponry for both sides of the conflict.
Some time in the future, Redmond and Blutarch are brought together through letters they believed were sent by the other; both having cheated death for many years realize their folly and propose a truce to create a machine that will make one of them pregnant and produce an heir. Gray, (who has returned after many years) reveals himself as their brother and arranger for this meeting, tries to convince them that instead of fighting over worthless gravel, they should take over the technology-savvy Mann Co., which he believes should be theirs by birthright. Neither Blutarch or Redmond agrees, being obsessed with gravel, and Gray kills them both.
Gray then uses his own army of robots to attack Mann Co. facilities all across the world. Saxton Hale hires the mercenaries, who are jobless since their employers were killed (RED and BLU unite as a result), to defend the Mann Co. sites against Gray's army of robots (who are themselves based on the mercenaries).