The book discusses the history, culture, and artwork of the Celtic people who ruled Europe from 500 BC to 1100 AD. It focuses on the Gauls, a prominent Celtic tribe that was a major adversary of Rome. The Celts were considered barbarians but were a fierce and passionate people known for their powerful warriors. A prominent part of Celtic culture was their art, including the torc necklace and depictions of women that showed a greater role for females than in Roman culture. Eventually, the Celts were assimilated into Christian European culture, though the interaction between the two influenced both and can be seen in illuminated manuscripts.