Editing Ab urbe condita (section)

==Use==
{{see also|Founding of Rome#Chronological disagreements}}
Prior to the Roman state's adoption of the [[Varronian chronology]] – created by [[Titus Pomponius Atticus]] and [[Marcus Terentius Varro]] – there were many different dates posited for when the city was founded. This state of confusion required picking a canonical founding date for one to use an AUC date. The Varronian chronology, constructed from fragmentary sources and demonstrably about four years off of absolute events {{circa|340&nbsp;BC}},<ref>{{Cite book |last=Forsythe |first=Gary |title=A critical history of early Rome |date=2005 |publisher=University of California Press |isbn=978-0-520-94029-1 |location=Berkeley |oclc=70728478 |page=279 }}</ref> placed the founding of the city on 21 April 753&nbsp;BC. This date, likely arrived at by mechanical calculation but accepted with a variance of one year by the Augustan-era {{lang|la|[[fasti Capitolini]]}}, has become the traditional date.<ref>{{Cite book |last=Cornell |first=Tim |title=The beginnings of Rome |date=1995 |publisher=Routledge |isbn=0-415-01596-0 |location=London |oclc=31515793 |page=73 }} Varro likely arrived at 753&nbsp;BC by counting seven generations of 35 years from his date for the founding of the republic in 509&nbsp;BC.</ref>

From the time of [[Claudius]] ({{Reigned|AD&nbsp;41|51}}) onward, this calculation superseded other contemporary calculations. Celebrating the anniversary of the city became part of imperial [[propaganda]]. Claudius was the first to hold magnificent celebrations in honor of the anniversary of the city, in AD 47,<ref>{{cite book |last1=Tacitus |first1=Cornelius |author1-link=Tacitus |editor1-last=Furneaux |editor1-first=Henry |editor1-link=Henry Furneaux |title=Annals XI|publisher=Clarendon Press |location=Oxford |page=17|edition=1907|quote=ludi saeculares octingentesimo post Romam conditam|lang=la}}</ref><ref>{{cite web |last1=Bilynskyj Dunning |first1=Susan |title=saeculum |url=https://oxfordre.com/classics/display/10.1093/acrefore/9780199381135.001.0001/acrefore-9780199381135-e-8233 |website=Oxford Research Encyclopedia of Classics |publisher=Oxford University Press |doi=10.1093/acrefore/9780199381135.013.8233 |date=20 November 2017|isbn=978-0-19-938113-5 }}</ref> the eight hundredth year from the founding of the city.<ref>{{cite book |last1=Hobler |first1=Francis |title=Records of Roman history, from Cnaeus Pompeius to Tiberius Constantinus, as exhibited on the Roman coins |date=1860 |publisher=[[John Bowyer Nichols]] |location=London |page=222}}</ref> [[Hadrian]], in AD 121, and [[Antoninus Pius]], in AD 147 and AD 148, held similar celebrations respectively.

In AD 248, [[Philip the Arab]] celebrated Rome's first [[millennium]], together with [[Ludi saeculares]] for Rome's alleged tenth [[saeculum]]. Coins from his reign commemorate the celebrations. A coin by a contender for the imperial throne, [[Pacatianus]], explicitly states "[y]ear one thousand and first", which is an indication that the citizens of the empire had a sense of the beginning of a new era, a ''Sæculum Novum''.