This book primarily covers Belgian historian Henri Pirenne's challenge to Edward Gibbon's assertion that the Germanic Tribes (Ostrogoths/Visigoths/Vandals) were primarily responsible for the decline and dissolution of the western Roman Empire. While Pirenne's thesis is sound, i personally find the arrangement of the book to be very awkward. The first 2/3rds of the book delve into various elements of subject matter ranging from numismatic evidence to agricultural conditions, and at points attempts to dismiss the Humanists, Protestant's, Voltaire's, Montesquieu's and other views on the decline, before ever stating the major argument of Pirene's thesis. 2/3rds of the way through the book, Pirenne's thesis is summed up in one long sentence.I can't imagine what Lyon thinks he is accomplishing by making arguments before ever stating Pirenne's position. In a formal logical argument in almost any discipline, a theory is posited, and then supporting evidence is presented to support it, or contradictory evidence is presented to disprove it. This book presents evidence, before Pirenne's thesis is ever presented to the reader. And Lyon never make's any clear argument of his own in my opinion. Someone familiar with Pirenne's theory before reading the book may not find it as awkward however.If you are interested in the decline and dissolution of the western Roman Empire, this book is worth reading. And Pirenne's argument is very persuasive, I suggest reading the first section of Chapter 3 if you are not familiar with Pirenne's works, and then returning to the beginning of the book. Since Lyon never makes any clear argument of his own, i would probably go straight to Pirenne's works myself. But once again, it is a short read with fairly good attribution. I found one or two assertions made in the work by Lyon that have no attribution. But overall, is fairly well documented.This book would be a good read as well for anyone interested in the lead up to the Medieval period. But for a serious historical analysis, i would suggest saving the 100 pages towards reading Pirenne's Mohammed and Charlemagne and his other available works.