What's Your Favorite Historical Counter Factor?

i just read an extraordinary book by a french oman named, i think, laurent binet. You've probably heard of it - called civilizations. It's really, i is marvellously precise piece of counter factual history. I urge you, i urge our listeners, after they buy your next, your new book, and my new book, to by civilization. The first one is what's your favourite historical counter factl have you got a watif that you particularly enjoy about history?