The Renegade Army is a group of former soldiers, featured as the group of secondary antagonists of Red Dead Revolver. They are one of the many reasons for the game's events.
A few years before the events of Revolver, Diego's men fought against a group of Americans. Diego's army defeated the American soldiers and captured one of them, a soldier named Griffon. Griffon, in exchange for his life, revealed the location of his and Nate Harlow's gold mine.
After taking control over the gold mine, Diego and Griffon became partners. The army also got assistance from the Black Elk Tribe.
Years later, Red started to hunt down the army, tracked down the army's location and attacked them. Red was captured by Daren, and was thrown to a jail near the army's base. Red was soon released, along with Buffalo Soldier, by Red's cousin Shadow Wolf, who was killed later by Daren.
After killing Daren, Red chased Diego's train, full of soldiers, weapons and gold. Red stopped the train, killed Diego's soldiers, and finally finished off Diego with a shot to the head, before returning to Brimstone in order to find Griffon.
After Diego's death, the army possibly disbands, having lost its base, its leader and most of its members.