Like a number of popular non-fiction books on King Arthur, this one can be divided into two parts. The first is an examination of (what the author considers to be) history; the second of (what the author considers to be) myth or legend. The 2nd part of this book seemed the better part, but that could just be because I know more about "Arthurian history" than Arthurian Romances. Below I restrict my comments largely to the 1st part.



The author, Frost, has grand promises, nothing less than "a [new] philosophy of history, using the Arthurian debate as the test." I'm afraid I could not detect much different from other books on this topic. The best aspect of part 1 is to point out the weakness of the "Arthur as a God" theories. But when it comes to making the alternate case, "Arthur as British high-king, c.500", Frost is much too reliant upon secondary sources, in particularly Morris' _The Age of Arthur_ (1973) which has been widely and justly criticized for its (ab)use of the primary sources. To give some examples:



1. Frost claims that "It is usually agreed that [the battle of Portsmouth in the Anglo-Saxon Chronicle] is the battle of Llongborth [in the Welsh poem Geraint son of Erbin]". In fact this is a claim by Morris which has very little evidence behind it. This identification is crucial to Frost's case that Arthur was high-king.



2. Frost claims that by the 490s, Irish settlements in Wales and Devon and Cornwall "had been completely overrun" and that "Archaeology indicates heavy fighting in Lindsey in the 490s". I'm guessing that these are based on claims by Morris, again with little basis. There is no hard evidence that Irish settled in Cornwall at all (and certainly not Devon), and absolutely no reliable dates for their expulsion here or anywhere. Direct archaeological evidence of fighting is rare anywhere in Britain, and it is impossible to date Anglo-Saxon cemeteries to anything like the precision Morris pretended.



There are also problems of relying too much on Geoffrey of Monmouth. Here are two examples:



1. Frost claims that the information about Arthurian battles in Geoffrey of Monmouth is independent from the Arthurian battle list in "Nennius". There is every reason to think that Geoffrey read Nennius. Geoffrey's changes and elaborations here are no more (in fact much less) than what he made in his account of Arthur's battles against the Romans, assuming that the latter is based on the history of Magnus Maximus (as Frost claims).



2. Frost says things like "Ambrosius Aurelianus came to power in a coup" when there is NOTHING suggesting this in any source prior to Geoffrey of Monmouth. (So much for Frost's supposed principle of only believing statements with independent corroboration.)



Finally, there are some downright errors. For example:



1. Frost gives a list of high-kings of the Britons including several rulers who are never described by this (or any similar term) in any source, poetic or otherwise: Rhun son of Maelgwyn (sic.), Owain son of Urien, Meurig of Gwent, and Cadfael of Gynedd. The list also omits two rulers in this period who actually were described as "King of the Britons" in near-contemporary sources: Selym of Powys, and Cerdic of Elmet.



2. Frost consistently mis-spells names of people and places. e.g. Caldonian for Caledonian. Durst and Durstan instead of Drust and Drustan. Vendotia for Venedotia. There are also some horrible English mistakes e.g. "may of have" for "may have had".



On a positive note, Frost does make one or two interesting observations that were new (at least I don't recall reading them before). e.g. Regarding the few post-Roman Britons known to have ruled in the southern and eastern provinces of Britain, arguably the earliest references to them use non-royal titles (governor, magistrate).



To conclude, it seems to me that Frost does do a reasonably good job of separating out what is almost certainly fiction in the Arthurian cycle, and tracing it to its origins in Celtic myths or the imaginiations of the Romancers. But if you are interested in what is possibly fact, with a sympathetic analysis at the evidence for the historical Arthur, "The Reign of Arthur" by Chris Gidlow is a far better book. Gidlow knows his primary sources, and uses them to justify his conclusions, rather than just relying on the opinions of other authors as does Frost.