Darrin was the brother of Dar and an Archenlander lord who lived during the reign of King Lune of Archenland. He cross-questioned Shasta about how many Calormenes were in the invasion force. Darrin fought at the Battle of Anvard with the Archenlanders and the Narnians against Prince Rabadash and the Calormene army. During the battle, he killed Ilgamuth of the Twisted Lip.
Darrin was voiced by Peter Moreton in The Horse and His Boy (Focus on the Family Radio Theatre).