Ab Urbe Condita - Relationship With Anno Domini

Relationship With Anno Domini

The Anno Domini year numbering was developed by a monk named Dionysius Exiguus in Rome during 525, as a result of his work on calculating the date of Easter. In his Easter table the year 532 AD was equated with the regnal year 248 of Emperor Diocletian. The table counted the years starting from the presumed birth of Christ, rather than the accession of the emperor Diocletian on 20 November 284, or as stated by Dionysius: "sed magis elegimus ab incarnatione Domini nostri Jesu Christi annorum tempora praenotare..." It is assumed Dionysius Exiguus intended either 1 AD or 1 BC to be the year of Christ's birth (a "year zero" does not exist in this calendar). It was later calculated (from the historical record of the succession of Roman consuls) that the year 1 AD corresponds to the Roman year DCCLIV ab urbe condita, based on Varro's epoch. This however resulted in that year not corresponding with the lifetimes of historical figures reputed to be alive, or otherwise mentioned in connection with the Christian incarnation, e.g. Herod the Great or Quirinius.

1 ab urbe condita = 753 before Christ

2 AUC = 752 BC

749 AUC = 5 BC

750 AUC = 4 BC (Death of Herod the Great)

753 AUC = 1 BC

754 AUC = 1 Anno Domini

755 AUC = 2 AD

759 AUC = 6 AD (Quirinius becomes governor of Syria)

2753 AUC = 2000 AD