 The reign of Charlemagne saw a revival in learning in Europe from the late eighth century , known as the Carolingian Renaissance . The Carolingian Empire collapsed in the late ninth century , while the tenth is seen as a period of decline , described as the " Age of Iron " by a Frankish Council in 909 . This negative picture of the period is increasingly challenged by historians ; in Michael Wood 's view " the first half of the tenth century saw many remarkable and formative developments that would shape European culture and history . " The Bible remained the primary fount of knowledge , but study of classical writers , who had previously been demonised as pagans , became increasingly acceptable . 
