Anno Domini
The terms anno Domini and before Christ are used when designating years in the Gregorian and Julian calendars. The term anno Domini is Medieval Latin and means "in the year of the Lord" but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "anno Domini nostri Jesu Christi", which translates to "in the year of our Lord Jesus Christ". The form "BC" is specific to English, and equivalent abbreviations are used in other languages: the Latin form, rarely used in English, is ante Christum natum or ante Christum.
This calendar era takes as its epoch the traditionally reckoned year of the conception or birth of Jesus. Years AD are counted forward since that epoch and years BC are counted backward from the epoch. There is no year zero in this scheme; thus the year AD 1 immediately follows the year 1 BC. This dating system was devised in 525 by the Eastern Roman monk Dionysius Exiguus but was not widely used until the 9th century. Modern scholars believe that the actual date of birth of Jesus was about 5 BC.
Terminology that is viewed by some as being more neutral and inclusive of non-Christian people is to call this the Common Era, with the preceding years referred to as Before the Common Era. Astronomical year numbering and ISO 8601 do not use words or abbreviations related to Christianity, but use the same numbers for AD years.
Usage
Traditionally, English follows Latin usage by placing the "AD" abbreviation before the year number, though it is also found after the year. In contrast, "BC" is always placed after the year number, which preserves syntactic order. The abbreviation "AD" is also widely used after the number of a century or millennium, as in "fourth century AD" or "second millennium AD". Since "BC" is the English abbreviation for Before Christ, it is sometimes incorrectly concluded that AD means After Death, which would mean that the approximately 33 years commonly associated with the life of Jesus would be included in neither the BC nor the AD time scales.History
The anno Domini dating system was devised in 525 by Dionysius Exiguus to enumerate years in his Easter table. His system was to replace the Diocletian era that had been used in older Easter tables, as he did not wish to continue the memory of a tyrant who persecuted Christians. The last year of the old table, Diocletian Anno Martyrium 247, was immediately followed by the first year of his table, anno Domini 532. When Dionysius devised his table, Julian calendar years were identified by naming the consuls who held office that year—Dionysius stated that the "present year" was "the consulship of Probus Junior", which was 525 years "since the incarnation of our Lord Jesus Christ". Thus, Dionysius implied that Jesus' incarnation occurred 525 years earlier, without stating the specific year during which his birth or conception occurred. "However, nowhere in his exposition of his table does Dionysius relate his epoch to any other dating system, whether consulate, Olympiad, year of the world, or regnal year of Augustus; much less does he explain or justify the underlying date."Bonnie J. Blackburn and Leofranc Holford-Strevens briefly present arguments for 2 BC, 1 BC, or AD 1 as the year Dionysius intended for the Nativity or incarnation. Among the sources of confusion are:
- In modern times, incarnation is synonymous with the conception, but some ancient writers, such as Bede, considered incarnation to be synonymous with the Nativity.
- The civil or consular year began on 1 January, but the Diocletian year began on 1 September.
- There were inaccuracies in the lists of consuls.
- There were confused summations of emperors' regnal years.
Another major theory asserts that Dionysius counted back 532 years from the first year of his new table, following an 532-year cycle established by the astronomical computations of Victorius of Aquitaine. Alternatively, Dionysius may have used an earlier unknown source, as the earlier Chronograph of 354 states that Jesus was born during the consulship of Caesar and Paullus.
It has also been speculated by Georges Declercq that Dionysius' desire to replace Diocletian years with a calendar based on the incarnation of Christ was intended to prevent people from believing the imminent end of the world. At the time, it was believed by some that the resurrection of the dead and end of the world would occur 500 years after the birth of Jesus. The old Anno Mundi calendar theoretically commenced with the creation of the world based on information in the Old Testament. It was believed that, based on the Anno Mundi calendar, Jesus was born in the year 5500 with the year 6000 of the Anno Mundi calendar marking the end of the world. Anno Mundi 6000 was thus equated with the end of the world but this date had already passed in the time of Dionysius.
The "Historia Brittonum" attributed to Nennius written in the 9th century makes extensive use of the Anno Passionis dating system which was in common use as well as the newer AD dating system. The AP dating system took its start from 'The Year of The Passion'. It is generally accepted by experts there is a 27-year difference between AP and AD reference.
The date of birth of Jesus of Nazareth is not stated in the gospels or in any secular text, but most scholars assume a date of birth between 6 BC and 4 BC. The historical evidence is too fragmentary to allow a definitive dating, but the date is estimated through two different approaches—one by analyzing references to known historical events mentioned in the Nativity accounts in the Gospels of Luke and Matthew and the second by working backwards from the estimation of the start of the ministry of Jesus.
Popularization
The Anglo-Saxon historian Bede, who was familiar with the work of Dionysius Exiguus, used anno Domini dating in his Ecclesiastical History of the English People, which he completed in AD 731. In the History he also used the Latin phrase ante incarnationis dominicae tempus anno sexagesimo, which is equivalent to the English "before Christ", to identify years before the first year of this era. Both Dionysius and Bede regarded anno Domini as beginning at the incarnation of Jesus Christ, but "the distinction between Incarnation and Nativity was not drawn until the late 9th century, when in some places the Incarnation epoch was identified with Christ's conception, i. e., the Annunciation on March 25".File:Charlemagne Agostino Cornacchini Vatican 2.jpg|thumb|right|Statue of Charlemagne by Agostino Cornacchini, at St. Peter's Basilica, Vatican City. Charlemagne promoted the usage of the anno Domini epoch throughout the Carolingian Empire.
On the continent of Europe, anno Domini was introduced as the era of choice of the Carolingian Renaissance by the English cleric and scholar Alcuin in the late eighth century. Its endorsement by Emperor Charlemagne and his successors popularizing the use of the epoch and spreading it throughout the Carolingian Empire ultimately lies at the core of the system's prevalence. According to the Catholic Encyclopedia, popes continued to date documents according to regnal years for some time, but usage of AD gradually became more common in Catholic countries from the 11th to the 14th centuries. In 1422, Portugal became the last Western European country to switch to the system begun by Dionysius. Eastern Orthodox countries only began to adopt AD instead of the Byzantine calendar in 1700 when Russia did so, with others adopting it in the 19th and 20th centuries.
Although anno Domini was in widespread use by the 9th century, the term "Before Christ" did not become common until much later. Bede used the expression "anno ante incarnationem Dominicam" twice. "Anno ante Christi nativitatem" is found in 1474 in a work by a German monk. In 1627, the French Jesuit theologian Denis Pétau, with his work De doctrina temporum, popularized the usage ante Christum to mark years prior to AD.
New year
When the reckoning from Jesus' incarnation began replacing the previous dating systems in western Europe, various people chose different Christian feast days to begin the year: Christmas, Annunciation, or Easter. Thus, depending on the time and place, the year number changed on different days in the year, which created slightly different styles in chronology:- From 25 March 753 AUC, i.e., notionally from the incarnation of Jesus, nine months before Christmas. This "Annunciation style" first appeared in Arles at the end of the 9th century, then spread to Burgundy and northern Italy. It was not commonly used and was called calculus pisanus since it was adopted in Pisa and survived there until 1750.
- From 25 December 753 AUC, i.e., notionally from the birth of Jesus. It was called "Nativity style" and had been spread by Bede together with the anno Domini in the early Middle Ages. This reckoning of the Year of Grace from Christmas was used in France, England and most of western Europe until the 12th century and in Germany until the second quarter of the 13th century.
- From 25 March 754 AUC. That second "Annunciation style" may have originated in Fleury Abbey in the early 11th century, but it was spread by the Cistercians. Florence adopted that style in opposition to that of Pisa, so it got the name of calculus florentinus. It soon spread in France and also in England where it became common in the late 12th century and lasted until 1752.
- From Easter. This mos gallicanus bound to a moveable feast was introduced in France by king Philip Augustus, maybe to establish a new style in the provinces reconquered from England. However, it never spread beyond the ruling élite.