Edward Gibbon, The Decline and Fall of the Roman Empire, 1776-1789Read about the other books on the list.
Although the whole of this gripping and majestic work is too much for most people in our hasty and hurried age, the (in)famous and important chapters 15 and 16 are an instructive read, for whose sake the whole is worth having. But the whole is worth having, too, for its salutary lessons regarding the fate of a great power, warning inheritors of its mantle what the future can hold.
The Decline and Fall of the Roman Empire is one of 110 books in the Telegraph's perfect library. Scott Turow hasn't read it, but he'd like to.