While it's not an easy or a casual read, I do highly recommend this book. It looks at the Mongol conquests in an entirety, instead of focusing on just one of the Kahns, or a particular battle.
The approach of this book is fresh, and tells us more about events going on elsewhere in the world and the effects it had on the Mongols. I was unaware of Christian-Mongol alliances during the Crusade era for example. The broad sweep of this book does mean however, that in some cases not as much detail as appreciated is given for certain events, as the author believes us to be familiar with the subject. I hoped there would have been more detail about Kublias invasion of Japan, for instance. A large book with a lot of small text, no photos but a few maps, its commentary of the conquest is told from a political perspective, with lots of names of people and places to confuse. All major battles are covered, as mentioned though it's not told from a military point of view, so don't expect tactics or weapon types.
I enjoyed this book, and I did learn a great deal. I would recommend it over any of the books that only talks about Ghengis Kahn, and doesn't take the big picture into account.