In the year 36 AD, he resigned the crown to his son Caradoc, and became Arch-Druid of the college of Siluria.
During his seven years in Rome, he became the first royal convert to Christianity and was baptised by the Apostle Paul, as was his son, Caradoc and the latter's two sons, Cyllinus and Cynon (Introduced the use of vellum into England.)