The Immortal Game. I've been nibbling at it over the past 3 months and I finally finished it last weekend.
Because I nibbled over 3 months, I don't have a whole lot of specific recall. Rather, I just remember that it was a good book that took a 10,000 foot view of chess over a millennium and a half.
The book goes back and forth between recounting history and the evolution of chess and the immortal game.
I learned how chess moved east to west and how the game had such an impact on culture and society. I learned of the different eras of chess and how the game was developed and viewed over hundreds of years.
The book flows very well. It was not boring; either from a chess player perspective or a non-chess player perspective.
I'm not going to get much into reviewing this - there are lots of reviews available. But if you're looking for a good, broad historical chess book, this would be a good start.