780

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	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	阴土羊年; (female Earth-Goat); 906 or 525 or −247; — to —; 阳金猴年; (male Iron-Monkey); 907 or 526 or −246

Millennium:	1st millennium
Centuries:	7th century; 8th century ; 9th century;
Decades:	760s; 770s; 780s ; 790s; 800s;
Years:	777; 778; 779; 780 ; 781; 782; 783;

Year 780 (DCCLXXX) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. 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.

Events

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]

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 marketplace, is founded by Charlemagne (approximate date).

The rise of Aldwych 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).

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).

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

^ Cutler & Hollingsworth (1991), pp. 501–502
^ David Nicolle (2014). The Conquest of Saxony AD 782–785, p. 19. ISBN 978-1-78200-825-5