en 852

852 in various calendars
Gregorian calendar	852; DCCCLII
Ab urbe condita	1605
Armenian calendar	301; ԹՎ ՅԱ
Assyrian calendar	5602
Balinese saka calendar	773–774
Bengali calendar	258–259
Berber calendar	1802
Buddhist calendar	1396
Burmese calendar	214
Byzantine calendar	6360–6361
Chinese calendar	辛未年 (Metal Goat); 3549 or 3342; — to —; 壬申年 (Water Monkey); 3550 or 3343
Coptic calendar	568–569
Discordian calendar	2018
Ethiopian calendar	844–845
Hebrew calendar	4612–4613
Hindu calendars
- Vikram Samvat	908–909
- Shaka Samvat	773–774
- Kali Yuga	3952–3953
Holocene calendar	10852
Iranian calendar	230–231
Islamic calendar	237–238
Japanese calendar	Ninju 2; (仁寿２年)
Javanese calendar	749–750
Julian calendar	852; DCCCLII
Korean calendar	3185
Minguo calendar	1060 before ROC; 民前1060年
Nanakshahi calendar	−616
Seleucid era	1163/1164 AG
Thai solar calendar	1394–1395
Tibetan calendar	阴金羊年; (female Iron-Goat); 978 or 597 or −175; — to —; 阳水猴年; (male Water-Monkey); 979 or 598 or −174

Millennium:	1st millennium
Centuries:	8th century; 9th century ; 10th century;
Decades:	830s; 840s; 850s ; 860s; 870s;
Years:	849; 850; 851; 852 ; 853; 854; 855;
	v; t; e;

Events

March 4 – Trpimir I, duke (knez) of Croatia, and founder of the Trpimirović dynasty, issues a first state document in Bijaći of all Slavonic peoples. In this Latin document Trpimir refers to himself as the "duke of the Croats" (dux Chroatorum), and to his country as the "state of the Croats" (regnum Chroatorum).
Presian I, ruler (khan) of the Bulgarian Empire, dies after a 23-year reign in which the Bulgarians have expanded into Upper Macedonia and Serbia. He is succeeded by his son Boris I, as monarch of Bulgaria.
Emperor Lothair I and his (half) brother Charles the Bald join forces to remove the Vikings from the island of Oscelles, in the River Seine. After this fails, Charles again pays them tribute (Danegeld).

A Viking fleet of 350 vessels enters the Thames Estuary before turning north, and engages the Mercian forces under King Beorhtwulf. The Mercians are defeated, and retreat to their settlements. The Vikings then turn south and cross the river somewhere in Surrey; there they are slaughtered by a West Saxon army, led by King Æthelwulf and his son Aethelbald, at Oak Field (Aclea).^[1]
King Æthelstan, the eldest son of Æthelwulf, is killed by a Viking raiding party. He is succeeded by his brother Æthelberht, who becomes sub-king of Kent, Essex, Surrey and Sussex (approximate date).
Beorhtwulf dies after a 12-year reign, and is succeeded by his son Burgred as king of Mercia.

Abd al-Rahman II, Umayyad emir of Córdoba, dies after a 30-year reign in which he has made additions to the Mosque–Cathedral at Córdoba. He is succeeded by his son Muhammad I, who will put down several revolts of the Muwalladun and Mozarabs in Muslim controlled areas in al-Andalus (modern Spain).

According to a 17th century account, the Andalusian inventor Abbas ibn Firnas makes a tower jump in Córdoba. He wraps himself with vulture feathers and attaches two wings to his arms. The alleged attempt to fly is not recorded in earlier sources and is ultimately unsuccessful, but the garment slows his fall enough that he only sustains minor injuries.

^ Paul Hill (2009). The Viking Wars of Alfred the Great, p. 14. ISBN 978-1-59416-087-5