I'm ashamed to admit that before I read this book I saw the world through a Pacific versus Atlantic lens. While that may be understandable given the history of the last century, for much of recorded history the Indian Ocean was arguably the most dynamic region in the world, bringing together not only different ethnicities and cultures but also different religions and bodies of knowledge.
While we may expect that China, India, and the Arab states played important roles in the trade activity over the centuries, one aspect of this volume that I enjoyed were the discussions about the African kingdoms and the significant roles they played. The Swahili coast in the South, Zanzibar, and Madagascar were important players in the Indian Ocean economic systems for centuries. The next time someone wants a resource on African history, I'm going to point them to this book (and yes, I realize it mostly covers East Africa).
The broad picture painted here isn't one of epic struggles between different nations or paradigms for dominance as much as it is how different people negotiated the terms of working with each other, albeit not always peacefully. This is not to say that the region was by any means utopian; indeed, the pervasiveness of piracy speaks not only to the danger those actors presented but also to the unsustainable political and economic conditions that necessitated piracy in the first place.
Highly recommended as a jumping off point for a study of this region.