|Died:||20 March 3027|
Piloting a Griffin named Ares at the time, Armstrong was defeated in an arena duel set in The Factory against Justin Allard on 20 March 3027. It turned out that Armstrong did not survive the destruction of his 'Mech.
Despite his loyalty to House Davion, MIIO head Quintus Allard felt that Armstrong had been a "problematic" character (like all six Davion-affiliated gladiator MechWarriors Justin Xiang Allard had killed by that time, including Billy Wolfson) and was happy to be rid of him, implying Armstrong was either a criminal, a troublemaker or otherwise a liability to House Davion.
Peter Armstrong had a wife and a daughter. His wife remarried to a surgeon named Roy Lear, and Armstrong's daughter was adopted though she initially refused to change her name as she idolized her father (as well as Philip Capet and Billy Wolfson) as martyrs. When Justin Allard was later revealed as a double agent and hero, his opponents including Armstrong were denounced traitors and she changed her name to Diedre Lear. She would later meet and eventually marry Justin Allard's son, Kai Allard-Liao, despite initially hating him because his father had killed hers.
- Warrior: En Garde, chapter 22
- Warrior: En Garde, chapter 36
- Blood Legacy, capter 21