Abstract
The Secret of Kells(Brendan to Kells no himitsu), set in medieval Irish monastery of Kells, was released in all parts of Japan in 2017. The Book of Kells is relatively famous and popular among Japanese people who are interested in Irish culture, Irish literature and Irish history. Most of them recognize this illuminated manuscript as a masterpiece of Celtic arts. I doubt the reliability of the concept of Celts or Celtic in pre-modern Irish history. I do not consider that it is suitable to use the term Celts or Celtic in medieval Irish history and culture.
This paper introduces recent studies of the Iron Age British archaeology, DNA researches of British people and the Book of Kells and prompts to reconsider about Celts.
