Reckoning time is central to all historical study, for history is essentially the story of change over time. Recently it has become standard in the Western world to refer to dates prior to the birth of Christ as B.C.E. (before the Common Era), replacing the earlier B.C. (before Christ) usage. This convention is an effort to become less Christian-
World history frequently deals with very long periods of time, often encompassing many millennia or centuries in a single paragraph or even in a single sentence. Such quick summaries may sometimes seem to flatten the texture of historical experience, minimizing the immense complexities and variations of human life and dismissing the rich and distinctive flavor of individual lives. Yet this very drawback of world history permits its greatest contribution to our understanding — perspective, context, a big picture framework in which we can situate the particular events, societies, and individual experiences that constitute the historical record. Such a panoramic outlook on the past allows us to discern patterns and trends that may be invisible from the viewpoint of a local community or a single nation. In the narrative that follows, there will be plenty of particulars — events, places, people — but always embedded in some larger setting that enriches their significance.