One of the problems with writing adventures set in 1st and 2nd century Ireland is that they sit way outside the usual literary genres. Very much in the ‘sword’ (rather than in the ‘sorcery’) of ‘sword and sorcery’, when you mix in Irish mythology they almost automatically get assigned to the ‘fantasy’ classification.
Fantasy is an area that sits uncomfortably with Irish people who know their history and culture, as mythology is always culturally based (not fantasy based).
Designing covers for these books therefore becomes even more complicated as you have to ensure the cultural integrity while also balancing expectations of people who expect them to fall into the fantasy realm. These are some of my own attempts to do so, to date.