en 880

880 in various calendars
Gregorian calendar	880; DCCCLXXX
Ab urbe condita	1633
Armenian calendar	329; ԹՎ ՅԻԹ
Assyrian calendar	5630
Balinese saka calendar	801–802
Bengali calendar	287
Berber calendar	1830
Buddhist calendar	1424
Burmese calendar	242
Byzantine calendar	6388–6389
Chinese calendar	己亥年 (Earth Pig); 3577 or 3370; — to —; 庚子年 (Metal Rat); 3578 or 3371
Coptic calendar	596–597
Discordian calendar	2046
Ethiopian calendar	872–873
Hebrew calendar	4640–4641
Hindu calendars
- Vikram Samvat	936–937
- Shaka Samvat	801–802
- Kali Yuga	3980–3981
Holocene calendar	10880
Iranian calendar	258–259
Islamic calendar	266–267
Japanese calendar	Gangyō 4; (元慶４年)
Javanese calendar	778–779
Julian calendar	880; DCCCLXXX
Korean calendar	3213
Minguo calendar	1032 before ROC; 民前1032年
Nanakshahi calendar	−588
Seleucid era	1191/1192 AG
Thai solar calendar	1422–1423
Tibetan calendar	阴土猪年; (female Earth-Pig); 1006 or 625 or −147; — to —; 阳金鼠年; (male Iron-Rat); 1007 or 626 or −146

Millennium:	1st millennium
Centuries:	8th century; 9th century ; 10th century;
Decades:	860s; 870s; 880s ; 890s; 900s;
Years:	877; 878; 879; 880 ; 881; 882; 883;

Year 880 (DCCCLXXX) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar.

Events

Battle of Cephalonia: A Byzantine fleet, under Admiral Nasar, is sent by Emperor Basil I to the Ionian Islands. Nasar defeats the Aghlabids in a night battle near Cephalonia (modern Greece).
May 1 – The Nea Ekklesia is inaugurated in Constantinople, by Patriarch Photius I, setting the model for all later cross-in-square Orthodox churches.^[1]^{[full citation needed]}^[2]^{[full citation needed]}

February 2 – Battle of Lüneburg Heath: King Louis III is defeated by the Norse Great Heathen Army at Lüneburg Heath. The Saxons are routed in a snowstorm; many drown in the river or are captured during the retreat.
Battle of Thimeon: King Louis III ("the Younger") defeats Vikings (probably Norsemen) from England, near Charleroi, north of the River Sambre. During the battle 5,000 Vikings are killed.
Battle of Fjaler: King Harald Fairhair moves east along the Norwegian coast with his fleet. He defeats his rival Atle Mjove at Fjaler in Sunnfjord, and lands with his longships at Tønsberg.
December – Treaty of Ribemont: Louis the Younger and the kings of the West Frankish Kingdom sign a treaty. The young Frankish monarch, Louis III, is reduced to merely Neustria.
Lambert I, duke of Spoleto, dies while besieging the city of Capua. He is succeeded by his son Guy II.
The oldest known mention is made of the city of Dortmund (approximate date).

Fujiwara no Mototsune, Japanese statesman, creates the position of regent (kampaku) for himself. The Fujiwara clan will be able to dominate the government for more than 3 centuries.
December 22 – Luoyang, eastern Chinese capital of the Dynasty, is captured by rebel leader Huang Chao, during the reign of emperor Xi Zong.

Pope John VIII issues the bull Industriae Tuae, creating an independent ecclesiastical province in Great Moravia, with archbishop Methodius as its head. Old Church Slavonic is recognized as the fourth liturgical language, besides Latin, Greek and Hebrew.
The first known Christian bishopric in Slovakia is established in the city of Nitra, with Wiching as bishop.