Laeg Mac Riangabra was the faithful friend and charioteer of
Cu Chulainn. The chariot of Cu Chulainn actually belonged to King Conchobar, because no other chariots were strong enough for the hero. As Cu Chulainn's driver, Laeg cared for the hero's horses – Liath Macha (Grey of Macha) and Dubh Sainglenn (Saingliu).
Not much is known about Laeg's family, except that he has two brothers who also served as charioteers to two other Ulster's champions. Sedlang Mac Riangabra was charioteer of
Laegaire Buadach, while Id Mac Riangabra was a charioteer of
Conall Cernach.
Laeg was usually present at most of Cu Chulainn's adventures, but his role is so small that we sometimes don't notice his presence. When we do notice Laeg, he usually provide wise advice to the young hero.
Laeg drove his master's chariot when Cu Chulainn confronted Medb's army alone in the epic
Táin Bó Cuailnge. When Cu Chulainn faced a difficult and deadly opponent, Laeg would try to exhort the hero to greater effort. When exhaustion, wounds and grief overcame Cu Chulainn by Fer Díad's death, Laeg attended to his master's wounds.
Laeg met his death, when Cu Chulainn again confronted Medb's army and her new allies. Lugaid, the son of
Cú Roi, hurled his spear at the hero, but missed at killed Laeg instead.