Old English hræfn (Mercian), hrefn; hræfn (Northumbrian, West Saxon), from Proto-Germanic *khrabanaz (source also of Old Norse hrafn, Danish ravn, Dutch raaf, Old High German hraban, German Rabe "raven," Old English hroc "rook"), from PIE root *ker- (2), imitative of harsh sounds (source also of Latin crepare "to creak, clatter," cornix "crow," corvus "raven;" Greek korax "raven," korone "crow;" Old Church Slavonic kruku "raven;" Lithuanian krauklys "crow").
Raven mythology shows considerable homogeneity throughout the whole area [northern regions of the northern hemisphere] in spite of differences in detail. The Raven peeps forth from the mists of time and the thickets of mythology, as a bird of slaughter, a storm bird, a sun and fire bird, a messenger, an oracular figure and a craftsman or culture hero. [Edward A. Armstrong, "The Folklore of Birds," 1958]
Old English also used hræmn, hremm. The raven standard was the flag of the Danish Vikings. The Quran connects the raven with Cain's murder of Abel; but in Christianity the bird plays a positive role in the stories of St. Benedict, St. Paul the Hermit, St. Vincent, etc. It was anciently believed to live to great old age, but the ancients also believed it wanting in parental care. The vikings, like Noah, were said to have used the raven to discover land. "When uncertain of their course they let one loose, and steered the vessel in his track, deeming that the land lay in the direction of his flight; if he returned to the ship, it was supposed to be at a distance" [Charles Swainson, "The Folk Lore and Provincial Names of British Birds," London, 1886].