The legends of many cultures include special bands of elite warriors, usually centered around a heroic king. This is not surprising, because the social and military structure of ancient societies often depended on groups of warriors to defend the community from outside threats. Naturally, the brave deeds of these warriors would sometimes become legends in the process of storytelling, and those legends would be used to inspire future generations of warriors.

One such example in Ireland is the “Red Branch Knights,” the circle of warriors who defended ancient Ulster from the rest of Ireland in the Ulster Cycle of Irish legend. The most famous of the Red Branch Knights was the hero Cuchullain, who was a kind of Irish Hercules. As a son (or even an avatar) of the Celtic god Lugh of the Long Arm, Cuchullain had many powers not available to the other Red Branch Knights, so he naturally dominates the Ulster Cycle.

However, there are a number of other Red Branch warriors with stories of their own, including the noble and doomed Ferdiad, the malicious Bricriu the Venomous and the tragic Naoise, the lover of Deirdre. Some of the stories of the Ulster Cycle have been lost over time, and based on the surviving titles we know some of these were probably about Red Branch warriors other than Cuchullain. Some scholars even believe that Cuchullain was a later addition to the Ulster Cycle, inserted by a tribe of Gaulish immigrants known as the Setanti. This is supported by two main facts: one is that Cuchullain's childhood name was supposed to have been “Setanta,” and the other is that the earliest references to the Ulster Cycle's “Tain” epic do not mention his name.