All this is purely mythical; but there are historical incidents to reckon with. About the year 520 a certain northern chief, called by the chronicler Chochilaicus (who is generally identified with the Hygelac of the epic), led a huge plundering expedition up the Rhine. After a succession of battles he was overcome by the Franks, but--and now we enter a legendary region once more--not until a gigantic nephew of Hygelac had performed heroic feats of valor, and had saved the remnants of the host by a marvelous feat of swimming. The majority of scholars now hold that these historical events and personages were celebrated in the epic; but some still assert that the events which gave a foundation for _Beowulf_ occurred wholly on English soil, where the poem itself was undoubtedly written. The rhythm of _Beowulf_ and indeed of all our earliest poetry depended upon accent and alliteration; that is, the beginning of two or more words in the same line with the same sound or letter. The lines were made up of two short halves, separated by a pause. No rime was used; but a musical effect was produced by giving each half line two strongly accented syllables. Each full line, therefore, had four accents, three of which (i.e. two in the first half, and one in the second) usually began with the same sound or letter. The musical effect was heightened by the harp with which the gleeman accompanied his singing.. The poetical form will be seen clearly in the following selection from the wonderfully realistic description of the fens haunted by Grendel. It will need only one or two readings aloud to show that many of these strange-looking words are practically the same as those we still use, though many of the vowel sounds were pronounced differently by our ancestors. ... Hie dygel lond Warigeath, wulf-hleothu, windige næssas, Frecne fen-gelad, thær fyrgen-stream Under næssa genipu nither gewiteth, Flod under foldan. Nis thæt feor heonon, Mil-gemearces, thaet se mere standeth, Ofer thæm hongiath hrinde bearwas ... They (a) darksome land Ward (inhabit), wolf cliffs, windy nesses, Frightful fen paths where mountain stream Under nesses' mists nether (downward) wanders, A flood under earth. It is not far hence, By mile measure, that the mere stands, Over which hang rimy groves.