in the Five Boroughs (modern East Midlands). Battle of Strangford Lough: King Halfdan I leaves for Ireland, in an attempt to claim the Kingdom of Dublin from his rival Bárid mac Ímair. He is killed in battle at Strangford Lough, and a probable interregnum follows in York. Ceolwulf II is installed as puppet king of Mercia. The west of the kingdom comes under Ceolwulf's rule, while in the east the Five Boroughs begin as fortified Danish burhs. The Vikings invade Wales once more, and King Rhodri ap Merfyn ("the Great") of Gwynedd, Powys and Seisyllwg is forced to flee to Ireland (approximate date). King Constantin I is killed fighting Viking raiders, at the "Black Cave" in Fife. He is succeeded by his brother Áed mac Cináeda as ruler of Alba (Scotland). Asia King Jayavarman III dies after a 42-year reign. He is succeeded by his cousin Indravarman I, as ruler of the Khmer Empire (modern Cambodia). By topic Religion October 23 – Photius I is reinstated as patriarch of Constantinople, after the death of Ignatius. Births January 31 – Wang Kon, founder of Goryeo (d. 943) September 10 – Eutychius, patriarch of Alexandria (d. 940) Ælfthryth, English princess and countess of Flanders (d. 929) Fujiwara no Kanesuke, Japanese nobleman (d. 933) Liu, Chinese empress of Qi (d. 943) Luo Shaowei, Chinese warlord (d. 910) Pi Guangye, Chinese chancellor (d. 943) Rudesind I, bishop of Mondoñedo (d. 907) Wang Rong, Chinese warlord (d. 921) Deaths August 5 – Ubayd Allah ibn Yahya ibn Khaqan, Abbasid vizier October 6 – Charles the Bald, Holy Roman emperor (b. 823) October 23 – Ignatius, patriarch of Constantinople Andrew the Scot, Irish archdeacon (approximate date) Bernard II, Frankish nobleman (approximate date) Carloman, Frankish abbot (approximate date) Constantine I, king of Alba (Scotland) Engelram, Frankish chamberlain Gérard II, Frankish nobleman (or 879) Halfdan Ragnarsson, Viking leader and 'king' of Northumbria Jayavarman III, king of the Khmer Empire (Cambodia) Johannes Scotus Eriugena, Irish theologian (approximate date) Musa ibn Bugha al-Kabir, Abbasid general Ōe no Otondo, Japanese scholar (b. 811) Savaric I, bishop of Mondoñedo (b. 866) Wang Ying, Chinese rebel leader References