AD 1 (I), 1 AD or 1 CE is the epoch year for the Anno Domini calendar era. It was the first year of the Common Era (CE), of the 1st millennium and of the 1st century. It was a common year starting on Saturday or Sunday,[note 1] a common year starting on Saturday by the proleptic Julian calendar, and a common year starting on Monday by the proleptic Gregorian calendar. In its time, year 1 was known as the Year of the Consulship of Caesar and Paullus, named after Roman consuls Gaius Caesar and Lucius Aemilius Paullus, and less frequently, as year 754 AUC (ab urbe condita) within the Roman Empire. The denomination "AD 1" for this year has been in consistent use since the mid-medieval period when the anno Domini (AD) calendar era became the prevalent method in Europe for naming years. It was the beginning of the Christian/Common era. The preceding year is 1 BC; there is no year 0 in this numbering scheme. The Anno Domini dating system was devised in AD 525 by Dionysius Exiguus.
|Gregorian calendar||AD 1|
|Ab urbe condita||754|
|Balinese saka calendar||N/A|
|Chinese calendar||庚申年 (Metal Monkey)|
2697 or 2637
— to —
辛酉年 (Metal Rooster)
2698 or 2638
|Coptic calendar||−283 – −282|
|Ethiopian calendar||−7 – −6|
|- Vikram Samvat||57–58|
|- Shaka Samvat||N/A|
|- Kali Yuga||3101–3102|
|Iranian calendar||621 BP – 620 BP|
|Islamic calendar||640 BH – 639 BH|
|Julian calendar||AD 1|
|Minguo calendar||1911 before ROC|
|Seleucid era||312/313 AG|
|Thai solar calendar||543–544|
127 or −254 or −1026
— to —
128 or −253 or −1025
- The Olmec 2 phase of the Olmec civilization begins; San Lorenzo and La Venta grow in population.
- Birth of Jesus, as assigned by Dionysius Exiguus in his anno Domini era according to at least one scholar. However, most scholars think Dionysius placed the birth of Jesus in the previous year, 1 BC. Furthermore, most modern scholars do not consider Dionysius' calculations authoritative, placing the event several years earlier (see Chronology of Jesus).
- Declercq, Georges (2000). Anno Domini: The origins of the Christian Era. Turnhout, Belgium: Brepols. pp. 143–147. ISBN 978-2503510507.
- Declercq, Georges (2002). "Dionysius Exiguus and the introduction of the Christian Era". Sacris Erudiri. Brussels: Brepols. 41: 165–246. doi:10.1484/J.SE.2.300491. ISSN 0771-7776.
Annotated version of a portion of Anno Domini
- Sources disagree regarding the starting day of Julian year AD 1 (see leap year error for further information).