Lynda D. asks: Who first came up with BCE, CE, BC and AD and what is the difference between them? BCE (Before Common Era) and BC (Before Christ) mean the same thing- previous to year 1 CE (Common Era). This is the same as the year AD 1  (Anno Domini); the latter means “in the year of the lord,” often … Continue reading What is the Difference Between BCE/CE and BC/AD, and Who Came Up with These Systems?