312

This article is about the year 312. For the number, see 312 (number). For other uses, see 312 (disambiguation).

Year 312 (CCCXII) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Constantinus and Licinianus (or, less frequently, year 1065 Ab urbe condita). The denomination 312 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Millennium:	1st millennium
Centuries:	3rd century 4th century 5th century
Decades:	290s 300s 310s 320s 330s
Years:	309 310 311 312 313 314 315

312 in various calendars

Gregorian calendar	312 CCCXII
Ab urbe condita	1065
Assyrian calendar	5062
Balinese saka calendar	233–234
Bengali calendar	−281
Berber calendar	1262
Buddhist calendar	856
Burmese calendar	−326
Byzantine calendar	5820–5821
Chinese calendar	辛未年 (Metal Goat) 3009 or 2802     — to — 壬申年 (Water Monkey) 3010 or 2803
Coptic calendar	28–29
Discordian calendar	1478
Ethiopian calendar	304–305
Hebrew calendar	4072–4073
Hindu calendars
- Vikram Samvat	368–369
- Shaka Samvat	233–234
- Kali Yuga	3412–3413
Holocene calendar	10312
Iranian calendar	310 BP – 309 BP
Islamic calendar	320 BH – 319 BH
Javanese calendar	192–193
Julian calendar	312 CCCXII
Korean calendar	2645
Minguo calendar	1600 before ROC 民前1600年
Nanakshahi calendar	−1156
Seleucid era	623/624 AG
Thai solar calendar	854–855
Tibetan calendar	阴金羊年 (female Iron-Goat) 438 or 57 or −715     — to — 阳水猴年 (male Water-Monkey) 439 or 58 or −714

Battle of the Milvian Bridge (312)

Events

By place

Roman Empire

• Constantine I crosses the Cottian Alps with an army (40,000 men) and defeats Maxentius's generals in three battles at Turin, Brescia and Verona. Maxentius's Praetorian Prefect Ruricius Pompeianus is killed in the fighting outside Verona.
• October 28 – Battle of the Milvian Bridge: Constantine defeats Maxentius at the Milvian Bridge, becoming the only Roman emperor in the West. Prior to the battle, he reportedly has a vision of a cross (labarum) with the phrase "in hoc signo vinces" ("In this sign you shall conquer"). This encourages him to convert to Christianity.
• October 29 – Constantine enters Rome; he stages a grand adventus in the city, and is met with popular jubilation. Maxentius' body is fished out of the Tiber and decapitated.
• Constantine forges an alliance with co-emperor Licinius, and offers him his half-sister, Constantia, in marriage. The Praetorian Guard and Imperial Horse Guard (equites singulares Augusti) are disbanded.
• Emperor Maximinus Daza campaigns unsuccessfully against the Armenians.

By topic

Religion

• Constantine I adopts the words "in hoc signo vinces" as a motto, and has the letters X and P (the first letters of the Greek word Christ) emblazoned on the shields of his soldiers.
• The Council of Carthage supports Donatism, which espouses a rigorous application and interpretation of the sacraments. These doctrines will be condemned by the Council of Arles (314).
• Constantine I promotes a policy of state sponsorship of Christianity, perhaps even becoming a Christian himself (see Constantine the Great and Christianity).

Births

• Dao'an, Chinese Buddhist monk and writer (d. 385)
• Huan Wen (or Yuanzi), Chinese general (d. 373)

Deaths

• October 28 – Maxentius, Roman emperor (b. 283)
• Clement of Ancyra, Christian bishop and martyr
• Guo Xiang, Chinese scholar and philosopher (b. 252)
• Huyan, Chinese empress of the Xiongnu state
• Ruricius Pompeianus, Roman praetorian prefect