The Christian Era, also known as the Common Era (CE) or Anno Domini (AD), is traditionally considered to have begun with the
presumed year of Jesus Christ's birth.
However, it's important to understand:
* It's an approximation: The actual year of Jesus' birth is debated, and most scholars believe he was likely born a few years *before* AD 1.
Therefore, while the Christian Era is *defined* as starting with the year of Jesus' birth, the historical reality of pinpointing that year is complex. The traditional starting point remains AD 1.