The name [Thrytho] was suggested by that of Cynethryth, Offa's queen.... The vindictive character here given to Thrytho is a poetic and veiled admonition addressed to Cynethryth[[78]].
Unfortunately this, like many another facile theory, is open to fatal objections. In the first place the poem of Beowulf can, with fair certainty, be attributed to a date earlier than that at which the historic Offa and his spouse lived. Of course, it may be said that the Offa episode in Beowulf is an interpolation of a later date. But this needs proof.
There are metrical and above all syntactical grounds
which have led most scholars to place Beowulf very early[[79]]. If we wish to regard the Offa-Thryth-episode as a later interpolation, we ought first to prove that it is later in its syntax and metre. We have no right to assume that the episode is an interpolation merely because such an assumption may suit our theory of the development of Beowulf. So until reasons are forthcoming for supposing the episode of Thryth to be later than the rest of the poem, we can but note that what we know of the date of Beowulf forbids us to accept Earle's theory that Thryth is a reflection of, or upon, the historic Cynethryth.
But there are difficulties in the way of Earle's theory even more serious than the chronological one. We know nothing very definitely about the wife of Offa II, except her name, but from a reference in a letter of Alcuin it seems clear that she was a woman of marked piety: it is not likely that she could have been guilty of deliberate murder of the kind represented in the Life of Offa II. The St Albans Life depends, so far as we know, upon the traditions which were current four centuries after her death. There may be, there doubtless are, some historic facts concerning Offa preserved in it: but we have no reason to think that the bad character of Offa's queen is one of them. Indeed, on purely intrinsic grounds we might well suppose the reverse. As a matter of history we know that Offa did put to death Æthelberht, the vassal king of East Anglia. When in the Life we find Offa completely exonerated, and the deed represented as an assassination brought about by the malice and cruelty of his queen, it seems intrinsically likely that we are dealing with an attempt of the monks to clear their founder by transferring his cruel deeds to the account of his wife.
So far, then, from Thryth being a reflection of an historic cruel queen Cynethryth, it is more probable that the influence has been in the reverse direction; that the pious Cynethryth has been represented as a monster of cruelty because she has not unnaturally been confused with a mythical Thryth, the wife of Offa I.
To this it may be objected that we have no right to assume remarkable coincidences, and that such a coincidence is
involved by the assumption that there was a story of a mythical Thryth, the wife of Offa I, and that this existed prior to, and independently of, the actual wedding of Offa II to a Cynethryth. But the exceeding frequency of the element thryth in the names of women robs this objection of all its point. Such a coincidence, far from being remarkable, would be the most natural in the world. If we look at the Mercian pedigree we find that almost half the ladies connected with it have that element thryth in their names. The founder of the house, Wihtlæg, according to Saxo Grammaticus[[80]], wedded Hermuthruda, the old English form of which would be Eormenthryth.
It is to this lady Hermuthruda that we must now devote our attention. She belongs to a type which is common in folk-tale down to the time of Hans Andersen—the cruel princess who puts her lovers to death unless they can vanquish her in some way, worsting her in a contest of wits, such as the guessing of riddles, or a contest of strength, such as running, jumping, or wrestling. The stock example of this perilous maiden is, of course, for classical story Atalanta, for Germanic tradition the Brunhilt of the Nibelungen Lied, who demands from her wooer that he shall surpass her in all three feats; if he fails in one, his head is forfeit[[81]].
Of this type was Hermuthruda: "in the cruelty of her arrogance she had always loathed her wooers, and inflicted upon them the supreme punishment, so that out of many there was not one but paid for his boldness with his head[[82]]," words which remind us strongly of what our poet says of Thryth.