1 BC (also written as 1 B.C.) is the year immediately preceding 1 AD (or 1 CE) in the proleptic Gregorian calendar and the Julian calendar. It marks the last year before the conventional beginning of the Anno Domini (AD) or Common Era (CE) dating system.
Definition and Nomenclature
- BC stands for "Before Christ," signifying the years prior to the presumed birth of Jesus of Nazareth.
- BCE (Before the Common Era) is an alternative and often preferred designation for the same period, providing a secular and culturally inclusive reference. Thus, 1 BC is equivalent to 1 BCE.
Calendar System and Year Zero
A crucial aspect of the AD/BC dating system is the absence of a "year zero." The year 1 BC is directly followed by 1 AD. This means that when transitioning from BC to AD, the count moves from 1 BC to 1 AD, rather than passing through a numerical zero.
The chronological sequence around this epoch is as follows:
..., 3 BC, 2 BC, 1 BC, 1 AD, 2 AD, 3 AD, ...
This system differs from astronomical year numbering, which does include a year 0 (equivalent to 1 BC in historical dating) and negative numbers (where -1 is equivalent to 2 BC, -2 to 3 BC, etc.).
Historical Significance
The concept of counting years "Before Christ" was established centuries after the events it describes. The Anno Domini system itself was devised by Dionysius Exiguus in the 6th century AD to date Easter, and it gradually gained widespread acceptance across Europe. The year 1 BC, therefore, serves as a conceptual pivot point in Western chronology, representing the final year before the commencement of the era widely used for historical and modern dating.