... We all know the romantic history of Vortigern's letter to Henghist and Horsa; of his visit to the Saxon camp; of Rowena and her cup; of the Isle of Thanet marked out by strips of cow-hide; and of the treachery of the Saxons at Stonehenge.  There is nothing morally impossible in the story as it was dished up for modern history, and it used to satisfy our ancestors before they had found out that a small king on the Welsh border could hardly have dealt with Thanet, and, moreover, that the Teutonic immigration had been going on for many years past on the eastern coast.
    As to the cow-hide and the massacre, they are said to be old Thuringian traditions; and the Welsh seem to have either invented or preserved the story of the fascinations of Rowena.  At any rate, they named her; for, alas for Saxon Rowena, there is nothing Teutonic in the word, and the Kymric form Rhonwen, white skirt, betrays its origin... (History of Christian Names, Yonge, 1884)