Christian Silversword, an American author, was traveling in Wales doing research for his newest book. The book was intended to be a fresh approach to the life and times of Prince Llywelyn, an important monarch who ruled Wales for 45 years in the late twelfth and early thirteenth centuries. One night during his trip, after falling asleep in his hotel bed in Dolwyddelan, the birth village of the prince, Christian somehow woke up in the thirteenth century and found himself investigating the murder of a local priest, who just happened to be the parish priest of the Prince himself. After meeting the Prince and his deadly personal bodyguard Gwillym at the scene of the crime, Christian was commissioned by Llywelyn to track down the murderer, with the help of a trusted servant Macsen, and somehow bring the criminal to justice.
Llywelyn, King of Gwynedd is a fantastical story, filled with wonder, danger and mystery and it details the cooperation between two very different people from two very disparate cultures and times and the profound effect they had on Welsh history.