The question that this book starts by addressing is "why Venice?" Why form a city among swampy islands? Venetians can almost give credit to Attila the Hun as a city founder since his destruction of the land-based city of Aquileia drove future Venetians to the islands in retreat. A future invasion by Charlemagne's son led them to unite and defend the least attractive part of the lagoon, which would become the city of Venice.
Being forced into an uninhabitable marsh led the Venetians to form a unique culture based on mercantilism. Unlike landlocked nations, the land available for growing crops and raising livestock was very limited, forcing Venetians to the sea where they successfully began trading with Constantinople, Cyprus and other Mediterranean nations. Eventually, against some Venetians' best judgment, they also began acquiring colonies on the mainland, leading them to become an empire by the 15th Century (though it would decline following the rise of the Turks in the 16th Century).
Madden also spends much of the book covering Venice's unique political system, which was a republic that lasted more than thirteen centuries - a time period during which most other governments were being ruled by royalty or dictators. Madden feels that it was the pragmatism of mercantile Venice that made them so successful in not letting one person gain too much power. The political system and people of Venice were always interested in stability and were thus able to deal with threats of despotism. It was only Napoleon's conquest that made them give up the form of government that at the time was the world's longest-surviving republic.
This book is also to be commended in its gripping storytelling of the battles, often taking place during the various Crusades to which Venice committed itself. Overall this is an excellent portrait of how a unique city in both geography and temperament became what it is now. The main problem that some of you might face in reading this book is that you will soon find yourself planning a trip to Venice to explore the history that Madden describes!