1.3 Regnal years of Roman emperors

Another system that is less commonly found than thought was to use the regnal year of the Roman emperor. At first, Augustus would indicate the year of his rule by counting how many times he had held the office of consul, and how many times the Roman Senate had granted him Tribunican powers, carefully observing the fiction that his powers came from these offices granted to him, rather than from his own person or the many legions under his control. His successors followed his practice until the memory of the Roman Republic faded (late in the 2nd century or early in the 3rd century), when they openly began to use their regnal year.

1.4 Indiction cycles

Another common system was to use the indiction cycle (15 indictions made up an agricultural tax cycle, an indiction being a year in duration). Documents and events begin to be dated by the year of the cycle (e.g., "fifth indiction", "tenth indiction") in the 4th century, and was used long after the tax was no longer collected. This system was used in Gaul, in Egypt until the Islamic conquest, and in the Eastern Roman Empire until its conquest in 1453.

1.5 Other dating systems

A great many local systems or eras were also important, for example the year from the foundation of one particular city, the regnal year of the neighboring Persian emperor, and eventually even the year of the reigning Caliph. The beginning of the notational year also varied from place to place, and was not largely standardized in Europe (except England) as January 1 until the 16th century. The most important of these include the Seleucid era (in use until the 8th century), and the Spanish era (in use in official documents in Aragon, Valencia, and in Castile, into the 14th century, and reportedly even later in Portugal).

2 After the Roman Empire

As the Roman Empire declined, imperial regnal year dating became sloppy, but remained the norm for 400 years in Christian Church circles. Use of consular dating ended when the emperor Justinian discontinued appointing consuls in the mid- 6th century. The last consul nominated was Anicius Faustus Albinus Basilius in 541. The Papacy was in regular contact throughout the Middle Ages with envoys of the Byzantine world, and had a clear idea — sudden deaths and deposals notwithstanding — of who was the Byzantine emperor at any one time.

The Anno Domini system was developed by a monk named Dionysius Exiguus (a Scythian) in Rome in 525, as an outcome of his work on calculating the date of Easter. Byzantine chroniclers like Theophanes continued to date each year in their world chronicles on a different and much more popular Judaeo-Christian basis — from the notional Creation of the World as calculated by Christian scholars in the first five centuries of the Christian era. These eras, sometimes called Anno Mundi , "year of the world" (abbreviated AM), by modern scholars, had their own disagreements. The most popular formulation was that established by Eusebius of Caesarea, a historian at the time of Constantine I. The Latin translator Jerome had made a comparison of Eusebius with certain dates deduced from the Old Testament which helped popularize Eusebius's AM count in the West.

3 Accuracy of dating

Almost all Biblical scholars believe that Dionysius was incorrect in his calculation, and that Jesus Christ was actually born between 8 BC and 4 BC. The latest bound for the birth of Christ is the death of Herod the Great which occurred in 4 BC. This is not a very controversial point, as no Christian denomination's theology requires the date to be 1 BC, and some minority beliefs do not accept that date at all.

4 The popularization of Anno Domini

The first historian or chronicler to use Anno Domini as his primary dating mechanism was Victor of Tonnenna , an African chronicler of the 7th century. A few generations later, the Anglo-Saxon monk Bede, who was familiar with the work of Dionysius, also used Anno Domini dating in his Ecclesiastical History of the English People, finished in 731. Bede was different from historians working in more important places in two ways: First, he was in Northumbria, outside the bounds of the later Roman Empire. Unlike the Mediterranean-focused countries of Italy, France, and Spain, his people had little knowledge of or interest in who the Roman Emperor was in any particular year. Second, he was confronted with the problem of seven Anglo-Saxon kingdoms and their overlapping regnal years. He had also previously written a chronicle going back to Creation, so he had the numbers at his fingertips. He adopted Anno Domini dating as a way of keeping track of the Anglo-Saxon kingdoms and trying to bring their dates into line with the fragmentary evidence he had for imperial regnal years. In this same history, he was the first to use BC and established the standard for historians of no year zero, even though he used zero in his computus.

On the continent of Europe, Anno Domini was first used as the dominant dating system by Charlemagne and his successors, having learned of it through the Northumbrian scholar Alcuin. It was this influence of the Royal Frankish court that popularized the usage and spread it east into German speaking territories. The Carolingian use of AD may well have had twin ideological reasons of breaking away from using the Byzantine era and defusing certain strains of apocalyptic thought.

Two lesser known systems competed for a while with the Anno Domini system. The earliest was the Era of Martyrs , which numbered years from the accession of Diocletian in 284, who launched the last yet most severe persecution of Christians. This system is still used officially by the Coptic and Ethiopian churches. The other system was to date from the Death of Jesus Christ, which as early as Hippolytus and Tertullian was believed to have occurred in the consulate of the Gemini ( AD 29), which appears in the occasional medieval manuscript.

5 Alternative methods in the modern era

The French Revolution and the Italian Fascists each seriously attempted to displace the Anno Domini system by instead dating from their own foundings — a non-royal regnal year system (see French Revolutionary Calendar). The Italian Fascists actually used the standard system along with Roman numerals denoting the number of years since the establishment of the Fascist government in 1922. Therefore, 1934, for example, was Year XII. Both attempts ultimately failed to replace the standard calendar. North Korea uses a system that starts in 1911, the year before the birth of their founder Kim Il-Sung, the year 2004 is "Juche 93" in this system because it is the 92nd year after the Juche leader's birth.

It is still very common in Taiwan to calculate dates from the founding of the Republic of China in 1912, and the official Japanese system numbers years from the accession of the current Emperor.

In the Islamic world, traditional Islamic dating according to the Anno Hegiræ (in the year of the hijra) era remains in use to a varying extent, especially for religious purposes. In Israel, the traditional Hebrew calendar, using an era dating from Creation, is in official use.

6 See also

• Calendar era
• Astronomical year numbering

7 References

• Declercq, Georges. Anno Domini: The origins of the Christian era. Turnhout: Brepols, 2000. BooksEnthsiast.com (despite beginning with 2, it is English)
• ———. "Dionysius Exiguus and the Introduction of the Christian Era". Sacris Erudiri 41 (2002): 165–246. An annotated version of part of Anno Domini.
• Richards, E. G. Mapping Time. Oxford: Oxford University Press, 2000. BooksEnthsiast.com

8 External links

• The Catholic Encyclopedia, s.v. "General Chronology"
• The Catholic Encyclopedia, s.v. "Christian Era"

Calendars Chronology

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