To speak of “empire” today is to evoke the history of China and of Rome, two great empires that vastly influenced the culture and development of half the globe. The whole world has been touched by their powerful examples, so that even someone writing, as I do, in a distant corner of North America, feels the history and influence of the Roman and Chinese empires every day. Nor are they unique. Something like “empire” has arisen wherever there was wealth and stability to support it. Rome and China had numerous rivals in the East and West who aspired to empire and sometimes achieved it. But Rome and China will remain the focus here because they are the paradigms of eastern and of western empire that illustrate the broader proposition. The cent...