A weirdly aimless, meandering book. It almost feels like a stream of consciousness piece rather than a serious attempt at outlining the history of the Crusades. The text is very dry and unfocused, and the author has a confusing tendency to repeat himself (for example, in the first chapter, he mentions "Constantinople, founded on the ancient Greek city of Byzantium, by Constantine, the first Christian emperor" with nearly the same wording twice, two pages apart). Sometimes he refers to the same people by different spellings of their names (for example, describing the caliph, he uses "Omar" and "'Umar" on the same page).
Further, he has a tendency to frequently veer off into tangential matters with little bearing on the topic at hand- for example, he spends a long paragraph, nearly filling a page, describing how Eleanor of Aquitaine supposedly retired to dress herself and her coterie as "amazons" after pledging to Bernard of Clairvaux join the Second Crusade, and then as an aside to THAT, mentions a fictional medieval description of a mythological Amazon queen. There's an entire chapter devoted to "Women and an Alternative Feudalism," concerning the role of women in the society of Outremer; while this is certainly an interesting subject, it's somewhat jarring to have it fill its own entire chapter in between a chapter about the rise of Nur ad-Din and Saladin, and a chapter about the fall of Jerusalem and the Third Crusade.
It's a very confusing, unhelpful book, and only really useful for the lists in the back of the book of the kings of Jerusalem, the Ayyubid sultans, and the popes at the time of the Crusades. The maps in the front of the book aren't very useful; one is of the Iberian peninsula, and one is of the Baltic, each showing the sites of major Crusade/Reconquista-related battles in the area- although the book doesn't spend much time at all on either theater of war, and is focused primarily on the Levant, Syria, and Egypt. The single map of the eastern Mediterranean shows, confusingly, the locations of the Crusader states, the routes taken by various parties of First Crusaders, battle sites (chosen apparently at random- it shows Myriokephalon and Heraclea, but not Manzikert or Ramla), and, in addition to these, the approximate borders of the Byzantine successor states (both Latin and Greek) resulting from the Fourth Crusade. And all of these bits of information are overlaid onto the same map, resulting in a confusing mess.
There's a biblography that takes up several pages, but the citations in the main text are sparse, frequently refer back to the same book several times in a row (so that each chapter only refers to maybe two or three books), and almost all the books cited via the footnotes in the text are tertiary sources written for the popular market.
There's useful information in this book, but it desperately needs extensive editing to be readable: that it was released as it is is almost shameful.