I'll be blunt: this book is a goddamned triumph.
I liked this book so much that I read all 800 pages of it even though the e-book had a glaring processing problem that caused it to insert a space after every double-f in the text (and some other cases I couldn't pin down a precise cause for). So, every time like "offered" was in the text, which was a surprisingly large number of times, it showed up as "off ered".
This was AMAZINGLY distracting. And normally the sort of thing that would cause me to bail out and wait for Amazon to fix the copy or something, but not in this case. The book, from Page One, was just too good.
Admittedly, I'll basically read anything even tangentially related to the Byzantine Empire. But even if you don't particularly care about that narrow topic, say you're just a "history buff" in general, this is the sort of work you absolutely should read.
Why? Well, Ms Hughes pulls off the herculean task of integrating classic history of the "which ruler sent what general to fight which enemy for what reasons" type, with the more modern aspects of "and how did that affect the culture, economy, mores, religion, etc., of the common man/woman/eunuch/slave of the polity?" type, AND does it all with a measure of style and competence that few authors are able to pull off successfully.
The book moves roughly chronologically through the "Three Cities" of the title; starting with the ancient Greek polis of Byzantion, then moving through the long epoch of the Roman/Byzantine Constantinople, then wrapping up with the world capital of Ottoman/Islamic/Turkish Istanbul. For such a long book, it moves remarkably briskly, helped along by economical chapter lengths and a vibrant writing style that generates that almost novel-esque sense of "just one more chapter" that few works of non-fiction ever achieve.
While firmly a history book, each chapter tends to start off with a wonderful and personalizing vignette from the author's own experience of researching for that chapter, situating the historical time about to be discussed in the modern age, which really helps pull the reader in and serves additionally as just great color. It also forces the reader to occasionally consider the randomness of history at time; sometimes your ancient relic becomes the still-venerated Hagia Sophia hundreds of years later. Other times, you're an equally-stunning ancient mosaic buried in the basement of a kebob joint behind a cell phone store. Such is fate.
VERY few histories give any nods to these also-rans of importance, and that Hughes does in this book jarred me into thinking for a bit about the caprice of history, the undeniable fact that what we today consider important about the past may not have been what the past considered important about itself, and that so much is left to the random chance of what managed to survive the millennia between a building or work of art's original period of importance and the reignition of interest in that original period by a much-later time. Basically, how many Michelangelo's "David"s are we missing out on today because nobody cared three hundred years ago and repurposed something beautiful into a roof for a barn?
It's this effect of the book I enjoyed most; at times I would read something that would force me to put the book down and just let my mind wander down a path it never had before, to consider some arcane detail of 1700's Constantinople that I hadn't thought of.
The breadth of knowledge Hughes shows here is also commendable; being able to write authoritatively about how an ancient Greek polis organizes itself politically is typically an entirely separate discipline from say describing in detail the personal politics of a reform-era Ottoman Sultan's harem. She handles both, and all of the other disparate topics that come up in a history of this breadth, with aplomb.
Bottom line, this book is just a delight. If you like good history, read it. If you're a fan of anything Byzantine or Ottoman, read it. If you like just plain good writing, read it. It's got that kind of cross-genre appeal few books pull off without being "lite" in their treatment of the topic, an accusation that absolutely cannot be laid at Ms Hughes' feet here; it is that rare bird, the Serious Work of History that is also an absolute joy to read. It gets my highest recommendation.