In a sense, this is a novel that concerns the identity of the Irish and how they define themselves. By exploring the history of the Irish and describing the various historical challenges that these people have faced over the centuries, the author makes clear the way in which Celtic mythology is such an important aspect of the Irish psyche and identity, particularly the importance of heroic figures who resist forces of evil, which are of course typified in the English who colonise Ireland.
In particular, you might like to consider the way in which this book depicts a fairy-tale image of Ireland before the English decided to annexe it. Uris describes the Irish as down-to-earth individuals but who nonetheless had rich mythological roots and the language that made every Irishman a poet. Celtic mythology is therefore shown to be at the heart of the identity of the Irish, and in particular their struggle and desire to be a free people and to embrace their cultural heritage. This is the struggle that is depicted in this work.