Millennium:	1st millennium
Centuries:	3rd century 4th century 5th century
Decades:	340s 350s 360s 370s 380s
Years:	363 364 365 366 367 368 369

366 by topic
Leaders
Political entities State leaders Religious leaders
Categories
Births Deaths

366 in various calendars
Gregorian calendar	366 CCCLXVI
Ab urbe condita	1119
Assyrian calendar	5116
Balinese saka calendar	287–288
Bengali calendar	−227
Berber calendar	1316
Buddhist calendar	910
Burmese calendar	−272
Byzantine calendar	5874–5875
Chinese calendar	乙丑年 (Wood Ox) 3063 or 2856 — to — 丙寅年 (Fire Tiger) 3064 or 2857
Coptic calendar	82–83
Discordian calendar	1532
Ethiopian calendar	358–359
Hebrew calendar	4126–4127
Hindu calendars
- Vikram Samvat	422–423
- Shaka Samvat	287–288
- Kali Yuga	3466–3467
Holocene calendar	10366
Iranian calendar	256 BP – 255 BP
Islamic calendar	264 BH – 263 BH
Javanese calendar	248–249
Julian calendar	366 CCCLXVI
Korean calendar	2699
Minguo calendar	1546 before ROC 民前1546年
Nanakshahi calendar	−1102
Seleucid era	677/678 AG
Thai solar calendar	908–909
Tibetan calendar	阴木牛年 (female Wood-Ox) 492 or 111 or −661 — to — 阳火虎年 (male Fire-Tiger) 493 or 112 or −660

Year 366 (CCCLXVI) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Gratianus and Dagalaifus (or, less frequently, year 1119 Ab urbe condita). The denomination 366 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.

Events

January 2 – The Alamanni cross the frozen Rhine in large numbers, and invade the Gallic provinces. They capture Alsace and a large part of the Swiss Plateau.
April – Battle of Thyatira: Emperor Valens defeats the troops of Procopius, bringing an end to his revolt; Serenianus and Marcellus are killed. Procopius flees the battlefield, but is executed by Valens.
Valens builds a pontoon bridge across the Danube, and drives the Visigoths farther north, where they will come under pressure from the advancing Huns.
Winter – Emperor Valentinian I appoints Jovinus, his Master of the Horse (Magister Equitum), general of the army. He defeats the Alamanni in three successive battles, and pushes them out of Gaul.

The Tabula Peutingeriana, a map showing Roman possessions and roads, is created about this time.

January 31 – Athanasius of Alexandria returns from his fifth exile. He has spent four months in his ancestral tomb outside Alexandria.
Buddhist monk Lè Zūn has a vision of "golden rays of light shining down on 1,000 Buddhas", resulting in the creation of the Mogao Caves.
October 1 – Pope Liberius dies after a 14-year reign and is succeeded by Damasus I as 37th pope. Romans unhappy with this choice elect the antipope Ursicinus.

Births