845

845 in various calendars
Gregorian calendar	845; DCCCXLV
Ab urbe condita	1598
Armenian calendar	294; ԹՎ ՄՂԴ
Assyrian calendar	5595
Balinese saka calendar	766–767
Bengali calendar	252
Berber calendar	1795
Buddhist calendar	1389
Burmese calendar	207
Byzantine calendar	6353–6354
Chinese calendar	甲子年 (Wood Rat); 3542 or 3335; — to —; 乙丑年 (Wood Ox); 3543 or 3336
Coptic calendar	561–562
Discordian calendar	2011
Ethiopian calendar	837–838
Hebrew calendar	4605–4606
Hindu calendars
- Vikram Samvat	901–902
- Shaka Samvat	766–767
- Kali Yuga	3945–3946
Holocene calendar	10845
Iranian calendar	223–224
Islamic calendar	230–231
Japanese calendar	Jōwa 12; (承和１２年)
Javanese calendar	742–743
Julian calendar	845; DCCCXLV
Korean calendar	3178
Minguo calendar	1067 before ROC; 民前1067年
Nanakshahi calendar	−623
Seleucid era	1156/1157 AG
Thai solar calendar	1387–1388
Tibetan calendar	阳木鼠年; (male Wood-Rat); 971 or 590 or −182; — to —; 阴木牛年; (female Wood-Ox); 972 or 591 or −181

Millennium:	1st millennium
Centuries:	8th century; 9th century ; 10th century;
Decades:	820s; 830s; 840s ; 850s; 860s;
Years:	842; 843; 844; 845 ; 846; 847; 848;

Year 845 (DCCCXLV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar.

Events

Byzantine–Arab War: A prisoner exchange occurs between the Byzantine Empire and the Abbasid Caliphate, at the River Lamos in Cilicia (modern Turkey). The exchanges last for 10 days, and the Byzantines recover 4,600 prisoners.^[1]^[2]

March 28 or 29 (Easter) – Siege of Paris: Viking forces under the Norse chieftain Ragnar Lodbrok enter the River Seine, with a fleet of 120 longships (5,000 men). They pass through the city of Rouen and plunder the countryside. King Charles the Bald assembles an army and sends it to protect Paris, the capital of the West Frankish Kingdom. Ragnar routs the enemy forces, and hangs 111 of their prisoners in honour of Odin.^[3] Charles — to keep them from plundering his kingdom — pays a large tribute of 7,000 livres (pounds) of silver or gold, in exchange for their leaving.^[4] The Vikings also sack the cities of Hamburg and Melun.
November 22 – Battle of Ballon: Frankish forces (3,000 men) led by Charles the Bald are defeated by Nominoe, count of Vannes, near Redon, Ille-et-Vilaine. After the battle, Brittany becomes a regnum 'kingdom' within the Frankish Empire.
Viking forces destroy Hamburg.

Great Anti-Buddhist Persecution: Emperor Wu Zong begins the persecution of Buddhists and other foreign religions in China, such as Zoroastrianism, Nestorian Christianity and Manichaeism. More than 4,600 monasteries, 40,000 temples and numerous shrines are destroyed. More than 260,000 Buddhist monks and nuns are forced to return to secular life.
March 6 – 42 captured Byzantine officials from Amorium are executed at Samarra, then the capital of the Abbasid Caliphate, after repeated failed attempts to convert them to Islam.

John Scotus Eriugena, Irish theologian, travels to France and takes over the Palatine Academy in Paris, at the invitation of Charles the Bald (approximate date).

Huart, Cl. (1986). "Lamas-Ṣū". In Bosworth, C. E.; van Donzel, E.; Lewis, B. & Pellat, Ch. (eds.). The Encyclopaedia of Islam, Second Edition. Volume V: Khe–Mahi. Leiden: E. J. Brill. p. 647. ISBN 978-90-04-07819-2.
Jones, Gwyn (2001). A History of the Vikings. Oxford University. ISBN 978-0-19-280134-0.
Sawyer, PH (2001). Illustrated History of the Vikings. Oxford University. ISBN 978-0-19-285434-6.
Toynbee, Arnold (1973). Constantine Porphyrogenitus and His World. London and New York: Oxford University Press. ISBN 0-19-215253-X.