Events By Place Europe Egbert of Wessex conquers Mercia and's recognized as Bretwalda. The Saracens ravage the coast of Dalmatia. Oldest known mention of the city of Wiesbaden (approximate date). Byzantine Empire Theophilus succeeds Michael II as emperor of Byzantium. Egypt The Nile freezes over. Asia The Bai kingdom of Nanzhao captures the city of Chengdu in Sichuan province, China. By Topic Religion Ansgar's appointed missionary to Sweden by Louis the Pious, at the request of the… (More on 829)