780

Year 780 (DCCLXXX) was a leap year starting on Saturday of the Julian calendar, the 780th year of the Common Era (CE) and Anno Domini (AD) designations, the 780th year of the 1st millennium, the 80th year of the 8th century, and the 1st year of the 780s decade. The denomination 780 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.

780 in various calendars

Gregorian calendar	780 DCCLXXX
Ab urbe condita	1533
Armenian calendar	229 ԹՎ ՄԻԹ
Assyrian calendar	5530
Balinese saka calendar	701–702
Bengali calendar	186–187
Berber calendar	1730
Buddhist calendar	1324
Burmese calendar	142
Byzantine calendar	6288–6289
Chinese calendar	己未年 (Earth Goat) 3477 or 3270     — to — 庚申年 (Metal Monkey) 3478 or 3271
Coptic calendar	496–497
Discordian calendar	1946
Ethiopian calendar	772–773
Hebrew calendar	4540–4541
Hindu calendars
- Vikram Samvat	836–837
- Shaka Samvat	701–702
- Kali Yuga	3880–3881
Holocene calendar	10780
Iranian calendar	158–159
Islamic calendar	163–164
Japanese calendar	Hōki 11 (宝亀１１年)
Javanese calendar	675–676
Julian calendar	780 DCCLXXX
Korean calendar	3113
Minguo calendar	1132 before ROC 民前1132年
Nanakshahi calendar	−688
Seleucid era	1091/1092 AG
Thai solar calendar	1322–1323
Tibetan calendar	ས་མོ་ལུག་ལོ་ (female Earth-Sheep) 906 or 525 or −247     — to — ལྕགས་ཕོ་སྤྲེ་ལོ་ (male Iron-Monkey) 907 or 526 or −246

Byzantine Empire with the themata (c. 780)

Empress Irene and her son Constantine VI

Events

By place

Byzantine Empire

• September 8 - Emperor Leo IV ("the Khazar") dies after a 5-year reign, in which he has been dominated by his wife Irene of Athens, an iconodule. He is succeeded by his 9-year-old son Constantine VI; due to his minority, Irene and her chief minister Staurakios exercise a regency over him.^[1]

Europe

• Saxon Wars: King Charlemagne decrees the death penalty for any subdued Saxon refusing Christian baptism. Meanwhile Widukind builds up rebel strength in northern Saxony.^[2]
• The city of Osnabrück, developed as a marketplace, is founded by Charlemagne (approximate date).

Britain

• The city of Aldwych rises as an important trading centre in London, under Mercian control. King Offa of Mercia possibly establishes a royal palace at Aldermanbury, on the site of the old Roman Cripplegate fort and amphitheatre (approximate date).

Asia

• King Hyegong of Silla is killed in a revolt, terminating the kingly line of succession of former ruler Muyeol. He is the architect of Silla's unification of the Korean Peninsula (see 668).

By topic

Religion

• Borobudur, a Buddhist temple complex in Magelang (modern Indonesia), is begun (approximate date).

Births

• Ahmad ibn Hanbal, Muslim scholar and theologian (d. 855)
• Frederick of Utrecht, Frisian bishop (approximate date)
• Guifeng Zongmi, Chinese Buddhist monk (d. 841)
• Hugh of Tours, Frankish nobleman (approximate date)
• Muḥammad ibn Mūsā al-Ḵwārizmī, Persian mathematician (approximate date)
• Rabanus Maurus, archbishop of Mainz (approximate date)
• Yunyan Tansheng, Chinese Buddhist monk (d. 841)

Deaths

• c. June 24 – Kume no Wakame, Japanese noblewoman
• August 19 – Credan, English abbot and saint
• September 8 – Leo IV, Byzantine emperor (b. 750)
• Dunchadh ua Daimhine, king of Uí Maine (Ireland)
• Hyegong, king of Silla (Korea) (b. 758)
• Khun Lo, founder of Luang Prabang (Laos)
• Approximate date – Himiltrude, queen consort of Charlemagne (b. c.742)