Editing 852 (section)

== Events ==
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=== By place ===

==== Europe ====
* [[March 4]] &ndash; [[Trpimir I of Croatia|Trpimir I]], duke (''[[Knyaz|knez]]'') of [[Duchy of Croatia|Croatia]], and founder of the [[Trpimirović dynasty]], issues a first state document in [[Bijaći]] of all [[Slavs|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 of Bulgaria|Presian I]], ruler (''[[Khan (title)|khan]]'') of the [[First Bulgarian Empire|Bulgarian Empire]], dies after a 23-year reign in which the [[Bulgars|Bulgarians]] have expanded into [[Upper Macedonia]] and [[Serbia]]. He is succeeded by his son [[Boris I of Bulgaria|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 [[Oissel|Oscelles]], in the [[Seine|River Seine]]. After this fails, Charles again pays them [[tribute]] ([[Danegeld]]).

==== Britain ====
* 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 [[Wessex|West Saxon]] army, led by King [[Æthelwulf]] and his son [[Aethelbald of Wessex|Aethelbald]], at Oak Field ([[Battle of Aclea|Aclea]]).<ref>Paul Hill (2009). ''The Viking Wars of Alfred the Great'', p. 14. {{ISBN|978-1-59416-087-5}}</ref>
* King [[Æthelstan of Kent|Æthelstan]], the eldest son of Æthelwulf, is killed by a Viking raiding party. He is succeeded by his brother [[Æthelberht of Wessex|Æthelberht]], who becomes sub-king of [[Kingdom of Kent|Kent]], [[Kingdom of Essex|Essex]], Surrey and [[Kingdom of Sussex|Sussex]] (approximate date).
* Beorhtwulf dies after a 12-year reign, and is succeeded by his son [[Burgred of Mercia|Burgred]] as king of [[Mercia]].

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

=== By topic ===
==== Aviation ====
* According to a 17th century account, the Andalusian inventor [[Abbas ibn Firnas#Armen Firman|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.

==== Religion ====
* [[Gandersheim Abbey]] in [[Lower Saxony]] (modern [[Germany]]) is founded by Duke [[Liudolf, Duke of Saxony|Liudolf of Saxony]].
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