This is the first literary-critical study of the Táin Bó Cúailnge in its entirety, and as an autonomous literary work. The key to a more deeply probing understanding of the semiliterate epic is the study of its characters: what they do and why they do it – why more important than what. Why reveals the differences between the various versions. Most promising is the multilayered Recension I, mainly preserved in Lebor na hUidre, which testifies of the keen interest of its compilers in the portrayal of the characters, while the version in the Book of Leinster, with its tendency to omit what might lessen the heroes’ prestige, pays for its greater unity with loss of depth.
The multifacetedness of the characters in the early version, combined with the deceptive simplicity of the plot, lends the work a remarkable pragmatism. Despite occasional baroque descriptions of battle frenzy, the main heroes Cú Chulainn and Fergus embody a heroism reined in by prudence. All through the war they do everything in their power to limit the use of force. Ailill and Medb represent a new type of ruler-entrepreneur, who seeks to realize his aim at the lowest possible cost and accepts failure matter-of-factly. So the epic has no fatal end-point. The greater part of the two armies are able return to their countries. The theme of mutual destruction is relegated to the Battle of the Bulls. The lasting antagonism between the North and the remainder of the island must have endowed the Táin with contemporary significance at various points in time, as the allusions to (near-)contemporary events suggest.