The Chronicle of the Princes records his death occurring at the Battle of Sunday on Anglesey in 873; the Annals of Wales record the two events in different years and Phillimore's reconstruction of its dates places Rhodri's death in 877. According to the Chronicle, Rhodri and his brother Gwriad were killed during a Saxon invasion (which probably would have been under Ceolwulf of Mercia, given that the Wessex forces under Alfred the Great were fighting Vikings in East Anglia at the time). The Annals record no great details of the death, but where the B text calls Gwriad Rhodri's brother, the A text has him as Rhodri's son instead. It is likely he was killed in battle given that all the sources call his son Anarawd's victory over the Mercians at the Battle of the Conwy a few years later "God's vengeance for Rhodri".