This paper addresses two questions. The first is whether the life of Deirdriu, as described in Longes mac n-Uislenn, can reasonably be said to correspond to the narrative pattern commonly referred to as the ‘heroic biography’. I argue that Deirdriu’s biography is, indeed, a heroic one, at least at the level of narrative structure, and can be shown to broadly follow the same progression as the biographies of more typical heroic biography subjects, and in particular that of Oedipus, who provides a model for many studies of the biography pattern. Moreover, this narrative kinship can be observed straightforwardly and without appealing to alternate versions of the pattern constructed to suit stories about women (i.e. those of Jezewski 1984 and Covington 1989). The second question is that of what Deirdriu’s biography tells us about the heroic biography itself. I argue that in recognising that Deirdriu not only has a heroic biography, but also that it is a conventional one, we gain insight into the use of the heroic biography as a narrative structuring device in stories about the lives of those who cannot be labeled ‘hero,’ according to any standard definition of the word.