The Knights of the Red Branch (赤枝の騎士, Akaeda no Kishi?) are the group of knights protecting Ulster. Compared to groups like the Knights of the Round Table, Cú Chulainn describes the group as in lacking "knightliness", in that those part of the group are free to do as they like so long as don't perform any actions disloyal to Ulster. Cú Chulainn, who claims he could easily pick a fight with an enemy country and forget about it the next day, felt there were so many people of suspect character among the knights that his own country needed to be watched more than potential enemies. The spell Ath nGabla is a curse of one-on-one combat passed down to the knights.
They also had a group of warrior apprentices for young warriors who had yet to come of age, around twelve or thirteen years old. They eventually became full-fledged knights after going through the "rites of warriorhood." 
- Fergus mac Róich - Said to be the pride of the Red Branch, he was the cornerstone of the order until he left in rage due to the actions of the king.
- Cú Chulainn