Harold is an English personal name. The modern name Harold ultimately derives from the Proto-Germanic *harja-waldaz, meaning 'military-power' or 'army-ruler'. The name entered Modern English via the Old English from Hereweald, which retained the same meaning and was prevalent in Anglo-Saxon England. The name's popularity in Viking Age England would also have been bolstered by the use of the Old Norse form Haraldr among Scandinavian settlers in the Danelaw.
Ancient
Chariovalda (d. 16), Batavian chieftain and Roman ally, killed near the River Weser
Medieval
Hagrold (fl. 944–954), also known as Harold, Scandinavian chieftain in Normandy
Harold Harefoot, or Harold I (c. 1015–1040), King of England from 1035 to 1040
Harold Godwinson, or Harold II (c. 1022–1066), the last Anglo-Saxon king of England and Earl of Wessex Harold, son of Harold Godwinson (fl. 1067–1098) Mstislav-Harald I Monomakh Grand Prince of Kyiv (1076–1132), grandson of Harold Godwinson, son of his daughter Gytha of Wessex Harold of Gloucester (died 1168), supposed child martyr and saint, allegedly murdered by Jews Harald Fairhair (850-932), the first King of Norway Arioald, king of the Lombards