October – Alan I (the Great), count of Vannes, and his rival Judicael, unite their forces to defeat the Vikings at Questembert (or 889). Judicael is killed, in a notable victory for the Bretons, with 15,000 Vikings crushed, some few 400 escaping to their ships. In command of a 'united' Breton force, Alan is able to drive the Vikings back to the Loire River. Alan becomes sole ruler of Brittany, and over the Frankish counties of Rennes, Nantes, Coutances and Avranches.
Lord Æthelred II of the Mercians is struck down with a debilitating illness. His wife, Princess Æthelflæd (a daughter of Alfred the Great) of Wessex, joins him as joint ruler of Mercia (approximate date).
The Aghlabids issue decrees according to which Jews and Christians are to wear a patch (ruq'a) of white fabric on their shoulder of their outer garment, with the patch for Jews depicting an ape and that for the Christians depicting a pig.[2][3]
^Gwatking, H. M., Whitney, J. P., et al. Cambridge Medieval History: Volume III–Germany and the Western Empire. Cambridge University Press: London (1930).