Events By Place Europe Prague Castle's founded. The Great Summer Army invades England and conquers East Anglia; the buildings destroyed by the Danish invaders include the abbey of Ely and the monastery of Peterborough. December 31 — The Danes are defeated by a Saxon army at Englefield, Berkshire. It's the first of a series of battles between Wessex and the Danes. Malta's conquered by Arabs from Sicily. Treaty of Meerssen: Charles the Bald and Louis the German divide Lotharingia amon… (More on 870)