The horse was the national emblem of the Saxons; and Hengist and Horsa are both old Teuton names for the animal, the first surviving in the German hengst and northern hest, the last in our ordinary word horse: while the High German hross has fallen into the modern ross.  White horses cut out in the chalky hill-sides of southern England from time immemorial, attest the antiquity of the symbol still claimed by the county of Kent, and by the Anglian-Continental kingdom of Hanover.
    In the old poem of Beowulf, however, Hengist is a Dane, invading and oppressing Finn of Friesland, and afterwards slain.  It is possible, then, that Hengist may after all be a mere mythic name erected into an ancestor by the Kentish monarchs.  Some have tried to derive hross from horen, to hear or obey, in honour of ;the noble creature's obedience; but it is in fact only another form of the ashva of India, to which ἵππος, equus, and the Keltic each have been traced;... (History of Christian Names, Yonge, 1884)