Garthek is a character who is mentioned by Thrynn.
One day, they came upon a caravan of farmers moving to a new village. Only the women and children remained after the initial attack. Garthek gave an order for the bandits to kill the survivors. Thrynn refused, and Garthek ordered his men to kill him. Thrynn had made some friends within the clan at the time, who quickly sided with him. The ensuing battle destroyed the clan, with the survivors heading their separate ways.
Thrynn left Garthek's head on a pike at the wreckage of the caravan.
- The Elder Scrolls V: Skyrim (mentioned only)