In the excellent collection of documents published by Penguin under the title Alfred the Great: Asser's Life of King Alfred and other contemporary sources, the editors Simon Keynes and Michael Lapidge offer an appendix on the subject of the tale of Alfred and the Cakes. Here, they attempt some analysis at the tale of the tale.

The earliest surviving version of the tale is in the Vita S. Neoti (The Life of Saint Neot), which is thought to have been composed in the late tenth century. It was later retold in the so-called Annals of St. Neots, probably compiled during the twelfth century. Although the emphasis of the story and the characterisation of Alfred and the shepherd's wife change from version to version, the essential details are there from the earliest version. Keynes and Lapidge then provide an explanation for why the story gained the popularity and the credence that it did:

Whatever the individual merits of the various versions, it was that in the Annals of St Neots which was known to Matthew Parker, who was the first to print Asser's Life of King Alfred, in 1574. Parker noticed the similarities between the Annals and Asser's Life, and deduced that the Annals were themselves written by Asser (when in fact it was the later compiler of the Annals who had made use of the Life); moreover, he had a far less scrupulous attitude towards the integrity of a text than a modern editor should have, and accordingly interpolated the story of Alfred and the Cakes exactly as he found it in the Annals at the appropriate point in his text of Asser's Life. Parker was followed in this respect by Camden (1602) and Wise (1722), and although the latter drew attention to the non-occurrence of the story in the manuscript of the Life, he explained that it was the manuscript that was defective. Petrie (1848) enclosed the story within square brackets, and was thus the first editor to mark it as an interpolation; Stevenson (1904) marked it as such more clearly, by putting it in small italics. But the 'damage' had been done: already popular before the sixteenth century, and then for long accepted on the highest authority as having been told by Asser himself, the story of Alfred and the Cakes gained wide circulation and attained the fame which it enjoys to the present day.

This explains, at least partly, why respectable historians gave the story some credence. Rather than being a later version of the tale, it was thought to have been described by the contemporary biographer of Alfred himself. But the power of a good story is its own force, and who can say that it would not still be one of the best known tales of Alfred's life had it not had this stamp of approval?