Salvadore Tyrell was the only survivor of a ploy by Sho-sa Victor Garreth that destroyed Tyrell's Raiders, a small mercenary unit, around 3024. Almost a year later he came to the attention of Duke Hassid Ricol. During a short interview the Duke determined that, although dispossessed, Tyrell was a resourceful MechWarrior who had been wronged by Lord Garreth, whom Ricol regarded as a liability to his nation.
Having lost several 'Mechs in his private service during a venture in the Lyran Commonwealth a few years before (implied to be the events narrated in Mercenary's Star (novel)), Ricol recruited him to create and train a private BattleMech company for the Red Duke.
Salvadore Tyrell did just that, and named the unit "Tyrell's Terrors" in memory of his late father's Dragon.
Tyrell's Terrors were subsequently deployed on several worlds to pursue the Duke's interests, including Rodigo and Verthandi. Following Duke Ricol's return from a venture in the Free Worlds League (implied to be the recovery of the Helm Memory Core as narrated in the novel The Price of Glory), the unit was ordered to meet Duke Ricol at the Kajikazawa starport to escort him to Luthien. On the sidelines, Salvadore Tyrell was given a chance to meet Victor Garreth at a reception on Kajikazawa. He jumped at the chance to exact vengeance for his father, and challenged Lord Garreth to a duel to the death in which he killed Garreth, with Ricol's consent.