Fergus mac Róich
Fergus mac Róich, a former king of the Ulaid in exile and Medb's lover, was chosen to lead the way for the army. On the way the army split in two. Ailill led one party, and Medb and Fergus, leading the other, took the opportunity to sleep together. But Ailill had sent his charioteer, Cuillius, to spy on them, and Cuillius stole Fergus's sword while he was "in flagrante". Ailill decided to forgive Medb on the grounds that she was probably trying to ensure Fergus' loyalty, and kept Fergus's sword safe but hidden.