This is a tremendous piece of scholarship. I won't even try to summarize the content - in a work of over 800 pages of text, this is impossible. Wickham takes the geographic regions which were part of, or heavily influenced by, the Roman Empire and examines how they evolved and developed, in multiple aspects, from the beginning of the 5th to the end of the 8th century. The book is divided into 12 chapters, focusing on four major subject areas; States, Aristocratic power-structures, Peasantries, and Networks. For each topic he divides the Post-Roman world into 10 distinct geographic regions and examines each individually. These regions are; North Africa, Egypt, Syria and Palestine, Byzantium, Spain, Central and Southern Gaul, Northern Gaul, Britain, Ireland, and Denmark. In some chapters he will examine regions together when development patterns are similar; most frequently combining Britain, Ireland and Denmark; however for the most part each of these 10 regions receives its own attention.
I was pleasantly surprised to find it able to maintain my interest and more readable than I anticipated. Each topical chapter is 60-100 pages long, which would be tedious, however when 8-15 pages are devoted to a given geographic region for each topic, it's much easier to work through.
There are several ways in which this book is truly outstanding. First is Wickham's use of sources. The book is heavily footnoted and he provides a great deal of evidence for most of his conclusions (I'll return to the exceptions in a moment). The sheer amount of referenced data is stunning and includes archaeology as well as written sources. He offers conjecture and hypothesis in some cases where there is not enough evidence to document a pattern of development. Most frequently this occurs for Britain, particularly in the chapter, "Peasants and Local Societies" where Wickham develops an entire hypothetical society based on how he believes it is most likely that British peasant society was structured. While this is an exception to Wickham's usually strict use of evidentiary sources, he is very careful - explicitly so - to state that this is a hypothesis based on his educated opinion, not something which can be proven through sources. He does this in several parts of the book and he is always careful to state where he's offering something which he believes is not provable.
The second way in which this book excels is in its insistence on avoiding generalizations. Even when examining ten different geographic regions, he further discusses differences which occur within these regions. The overall impression is that in order to truly study medieval history, one must focus on smaller, regional areas and must, at all costs, avoid generalizing for all Post-Roman societies.
As for the information itself, it is an eye-opener. In the broadest sense, Wickham argues that the relative success of Post-Roman societies is strongly tied to how that society was structured within the Empire. Regions which were tied closely to Rome through the state, through taxation and commerce, were those most profoundly depressed in the Early Medieval Period while those which were largely agrarian and land-owning were less affected. In this way he shows that regions such as North Africa and the Spanish Coastal Regions were profoundly impacted while areas such as Gaul, (particularly in the North) and Egypt were less affected and in fact remained relatively wealthy through the Early Medieval Period. He utilizes a variety of topics to illustrate this including exchange networks, aristocratic wealth, societal urbanization and state-building.
I disagree with some of his views. He argues for a much greater level of peasant land-owning and wealth through this period. In and of itself this is supportable however at one point he argues that as aristocracies grew weaker and poorer, peasant society became wealthier because the aristocratic wealth must have been transferred to peasants. I am unconvinced by this. Societies have become poorer at all levels, from the wealthy to the poor, without this type of wealth transfer. During the American Great Depression, all levels of society were poorer than they were in the mid-1920's. The loss of wealth by the elite of that time was not transferred to the poor and middle class. I don't know that this didn't happen in the Medieval period, however I find this argument, in and of itself, unconvincing. While peasant society very likely became stronger in relative terms when compared to aristocracies, I am uncertain if this holds true when discussing absolute wealth.
Another argument he has put forward is that peasant families voluntarily reduced their reproduction rather than following Malthusian principles as a response to a poorer society. Again, this may have happened, as it did in the late Empire, however I am unconvinced. To be fair, in both of these cases he is careful to state these as beliefs which he cannot support based on the evidence. I find conjecture, when given with this caveat, perfectly acceptable.
I do have one substantial complaint; when discussing how society began to re-form around a strengthening aristocracy later in the period, he ignores what role the Church may have played. Certainly churches and monasteries became major landholders during the period covered and I have often seen it argued that the Church was one of the main institutions that helped society retain some semblance of structure. This is largely ignored, whether Wickham agrees with it, or has evidence to debunk it.
Even so, this is a monumental, wonderfully informative work. After reading this it is obvious why generalizations such as "society collapsed following the end of the Roman Empire" or, "the end of the Roman World was a transformation which resulted in little loss of wealth or societal structure" cannot be supported. Each of these statements is true - but only for specific regions, not for the entire Post-Roman World.
I highly recommend this book. I believe there is a new trilogy of survey works which anyone studying the Early Medieval Period should try to own; McCormick's "Origins of the European Economy", Heather's "The Fall of the Roman Empire" and Wickham. These three books have made great strides both in providing a great deal of information as well as studying Late Antiquity in such detail as to make shallow generalizations unnecessary.