In order to understand the rise of Islam (says this book I'm reading) you first have to understand the imperial politics and religious controversies of Byzantium and the Persian Empire in the 6th and 7th centuries. I've heard of some of the people involved- Justinian, Simeon the Stylite (I watched Bunuel's Simon of the Desert just the other day) but most of them- not just individuals but tribes and nations and sects- are entirely new to me. They bounce around the landscape of the Middle East, full of their own importance, calling in at places we now know by different names, conquering and converting and committing atrocities- and it's very difficult to keep them all straight in one's head. There's nothing like reading ancient history to put contemporary issues and agonies in perspective. Who in fifteen hundred years is going to recognize the names Obama, Romney, Putin, Cameron, Merkel? A few specialists, perhaps.