Arwald (died 686 CE) was the last Jutish King of the Isle of Wight and last pagan king in Anglo-Saxon England until the Vikings in the 9th century. His name may have been "Arwald" or "Atwald" - Bede's script is often difficult to read. PASE has "Arwald".
Nearly all we know of him is from Bede's Historia ecclesiastica gentis Anglorum, which describes the invasion of the Isle of Wight by Caedwalla, a Wessex King, who, with merciless slaughter, endeavoured to destroy all the island's inhabitants and replace them with his own followers. Caedwalla had also vowed to give a quarter of the Isle of Wight to St. Wilfrid and the Church.
Arwald was killed in battle, but his two younger brothers escaped to the Great Ytene Forest (now called the New Forest). They were betrayed to Caedwalla and taken to a place where he "was in hiding with his wounds" at Stoneham, near Southampton. Shortly before they were put to the sword they allegedly converted to Christianity by the intervention of an abbot, being described by Bede as "the first fruits" of the massacre because of this conversion.
Thus canonised, their names are unknown, but they are called collectively "St. Arwald"- after their pagan uncle (who died fighting Christianity).