8th century: Carolingian Renaissance: monastic and cathedral schools were established everywhere to train men of civil service, Palace School at Aahen (in Abbasside Caliphate: Islamic Golden Age, “House of Wisdom”)
Barbarian invasions: the Viking Age 793-1066, raids of Magyars (Hungarians) 795-1001, invasions of Saracens (Arabs, Berbers, Moors and Turks) first occupation in 8th century, continued in 9th-11th.