At one point I found myself asking why I had picked this book. I suppose what attracted me was that it appeared to promise absolutely no point of contact between its subject matter and our own confused and confusing times. Sometimes it is relaxing to retreat into the past for a while. It was also a subject about which I knew almost precisely nothing, apart from what I had gleaned from reading Malory's Morte d'Arthur: hazy mental pictures composed of a Very Important Lady's garter falling off, Blondel doing an exhausting tour of free gigs outside every castle in Germany until he found Richard the Lionheart, and Monty Python's limbless Black Knight saying "It's just a scratch". Or to put it another way, if you had asked me to distinguish between the codes of chivalry and the Code of the Woosters I would have been pretty much at a loss.

Well, it is always good to replace a mental vacuum with something rather more substantial  although this does prevent me from fulfilling one of the reviewer's occasionally necessary duties: pointing out when an author has made a factual error. Saul could have told me that knights of a certain order rode around on swans, and I would have been obliged to take him at his word. Not that he does, of course. Sometimes the mental furniture is rearranged to reduce clutter  or, usefully, to make things less straightforward. I had, for example, ever since reading Harriet Harvey-Wood's The Battle of Hastings, been rather indignant about the Norman invasion, which in that book is presented as the wholly lamentable destruction of a reasonably civilised and, by the standards of the times, progressive way of life.

According to Saul, though, the Norman invasion marked the exact point at which the victors did not automatically take the lives of the vanquished, which is apparently what had happened hitherto. Actually, here I can at least point to an inconsistency between the differing historical perspectives of Saul/Harvey-Wood: the latter quotes evidence that William's forces murdered 100,000 innocent people; while Saul cites an example of William sparing the citizens of Exeter  after, admittedly, blinding one of his hostages just to remind them that there was a new sheriff in town  and points out that the Anglo-Saxons, when they had the chance, put fleeing Norwegians and Vikings to the sword. (One tends not to welcome a defeated invader into the home.)

But the book is full of solid, engrossing history. For a long time, chivalry was regarded by historians as little more than a cosmetic gloss on the business of fighting; but lately it has been reinterpreted as an essential element of the social order, and a complex way of keeping the potential threat of a free-floating force of armed and bored men at bay, or on one's side. The book serves, too, as a primer in medieval history, and the political and martial achievements of this country's rulers from William to Henry VII. I found myself able to attribute human characteristics to the succession of names and regnal numbers. Saul is a clear-eyed historian, not one to be taken in by popular legend  the story of the origin of the Order of the Garter involving a lady dropping hers does not merit even a dismissal, and the story of faithful Blondel is, we are advised, a fiction.

Of course, nothing is completely irrelevant to the present day, even over a gap of centuries. The roots of our parliamentary democracy lie in the soil of chivalry, with knights roughly corresponding to the Commons and the nobility to the Lords: a more fluid system than that in rigid, caste-bound Europe; there is still a College of Arms, devoted to establishing and policing the distinctions between various coats of arms; and the appeal of the Arthurian legends persists. And each year, on the Monday of Royal Ascot Week, there is still a ceremony in the grounds of Windsor Castle in which the members of the Order of the Garter gather together. It may be a purely symbolic occasion, but the tradition goes back well over 600 years.