Christian Era

The Christian Era is a system of chronology that dates from the birth of Christ. Its epoch, or beginning, is traditionally set at January 1, 754 years after the founding of Rome (AUC). Years are counted as BC (before Christ) or AD (anno Domini, meaning "in the year of the Lord"). There is no year zero; 1 BC is followed directly by 1 AD.12

This dating system was developed by Dionysius Exiguus around 525 AD, who aimed to number years from the Incarnation of Jesus Christ rather than from the reign of Emperor Diocletian. While Dionysius's calculation placed Christ's birth in 753 AUC, historical accounts suggest it occurred earlier, by 750 AUC at the latest. The method was popularized by the English scholar St. Bede the Venerable in the 8th century through his writings, notably the Ecclesiastical History of the English People. The Christian Era gradually became the standard throughout Europe, though its adoption varied by region, with some areas not fully embracing it until the 15th century.23