Anno Domini

Anno Domini (Medieval Latin : “in the year of the Lord”), shortened as AD or A.D., is used to refer to the years after the birth of Jesus. AD is also a shorthand for Christian Era.Abate, Oxford Pocket Dictionary and Thesaurus, s.v. "A.D." Likewise, Before Christ, shortened as BC or B.C., is used in English to refer to all years before our present time (AD or A.D.).

Overview
In past centuries, AD came before the year but after a century or millennium in written documents. For example, a person would write AD 2014 but 21st century AD or 3rd millennium AD. There is no zero year in this system. This means that the year A.D. 1 follows the year 1 B.C.

Some people mistakenly interpret “A.D.” as “after death.” The shorthand “A.D.” was originally placed before the year number (e.g. A.D. 145), while “B.C.” was often placed after the year number (e.g. 145 B.C.). Nowadays, it is more usual to put both shorthands after the year numbers (e.g. 145 AD; 145 BC). Such dating system was meant to signal the year of Christ's birth, but some modern scholars said that Jesus was born a few years earlier than commonly believed.

History
Classical antiquity
The system for working out the years was invented by Dionysius Exiguus in around AD 525. He fixed the point Anno Domini, which is used to number the years of both the Gregorian calendar and the Julian calendar. He used it to identify the several Easters in his Easter table. He did not use it to date any historical event.

When he devised his table, Julian calendar years were identified by naming the consuls who held office that year — he himself stated that the “present year” was “the consulship of Probus Junior [Flavius Probus]”, which he also stated was 525 years “since the incarnation [coming in bodily form] of our Lord Jesus Christ”.

How he arrived at that number is unknown. He invented a new system of year numbering to replace the Diocletian years that had been used in an old Easter table because he did not wish to continue the memory of a tyrant who persecuted Christians.

Middle Ages
The Anno Domini calendar era became dominant in Western Europe only after it was used by the Venerable Bede to date the events in his Ecclesiastical History of the English People, completed in 731. The French emperor Charlemagne made it popular in continental Europe. The Anno Domini system was not used in certain parts of Europe until the 15th century. For instance, Portugal used a different system called the Spanish era until 1422.

References

Category:Culture
Category:Periods and ages in history
Category:Calendars
Category:Chronology
Category:Christianity
Category:History of Asia
Category:History of Europe