What are the Deryni books?

The series is set in the land of Gwynedd, one of the fictional Eleven Kingdoms. Gwynedd itself is a medieval kingdom similar to the British Isles of the 10th and 12th centuries, with a powerful Holy Church (based on the Roman Catholic Church), and a feudal government ruled by a hereditary monarchy. The population of the Eleven Kingdoms includes both humans and Deryni, a race of people with inherent physic and magical abilities. Throughout the course of the series, relations between humans and Deryni result in ongoing political and religious strife that is often interconnected with the individual lives of the main characters. While the plots of the novels often involve political, ecclesiastical, and military conflicts on a grand scale, they are counter-balanced by details of the characters' personal lives. Neither race is depicted as inherently "good" nor "evil", as both humans and Deryni are depicted as protagonists and antagonists at various points of the series. Additionally, the novels often depict the characters engaging in various forms of magic, and such scenes vary in importance from minor events to significant plot points.