He is highly praised by the chroniclers for converting the island to Christianity – a feat which, according to the Vulgate Estoire del Saint Graal, was prompted by Peter, a relative of Joseph of Arimathea, who arrived in Britain during Lucius’s reign. Peter befriended Lucius and became his vassal after the latter’s conversion. Lucius asked Pope Eleutherius to send Christian bishops to Britain. Under his reign, parishes and dioceses were set up in London, York, and Caerleon, and the old heathen temples were demolished. Those who refused to convert were destroyed.
When he died, however, he left no heir, and the Britons and Romans fought over who should be crowned in Lucius’s place. The fighting lasted for several generations and resulted in a series of impotent kings before the kingdom was settled briefly under Asclepiodotus.
According to Nennius, Lucius received his Baptism in 167, but Geoffrey says that he died in 156, and Layamon places his death in 160. Interestingly, the confused fourteenth-century Short Metrical Chronicle places his reign after Arthur’s.
Historia Brittonum | Probably Nennius, early 9th century
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155
Brut | Layamon, late 12th century to mid-13th century
Vulgate Estoire del Saint Graal | 1220-1235
Short Metrical Chronicle | 1307