Paul W. answered 04/12/19
Dedicated to Achieving Student Success in History, Government, Culture
Without question, Charlemagne's patronage of learning made a significant contribution to preserving the Classical literature of Ancient Rome. However, the assertion that Charlemagne is responsible for 'Saving Latin Literature' is an obvious exaggeration.
As truly remarkable as Charlemagne's Carolingian Empire was, it was not the only civilization that existed in Europe following the end of the Western Half of the Roman Empire in 476. The Eastern Half of the Roman Empire, which survived the 'Fall' of the Western Half, not surprisingly preserved a great deal of Classical literature (the Eastern Half of the Roman Empire that survived throughout the Middle Ages is known as the Byzantine Empire).
Classical Roman culture didn't simply disappear along with the government of the Western Half of the Roman Empire. The so-called 'Barbarian' peoples who established kingdoms in Post-Roman Gaul, Italy, Iberia, and North Africa liked what they found and maintained, as best they could, Roman institutions. Moreover, these 'Barbarian' peoples were Christians and cooperated with the Christian Church, a Church that served as the primary repository of learning and knowledge (after all, in order to use the Bible and other religious texts, the clergy had to be literate).
Among the more unlikely peoples who helped to preserve Classical literature were the Irish, whose homeland had never even been part of the Roman Empire. But the 5th century Romano-British missionary, St. Patrick, brought Latin literacy along with Christianity to Ireland. At least by the 7th century the numerous monasteries in Ireland were accumulating collections of Classical literature that they copied and re-copied. Beginning in the late 6th century Irish missionaries and self-exiled scholars began to travel through Europe, converting pagans, founding monasteries, and promoting Latin learning. Indeed, Irish monks and English monks from monasteries founded by the Irish played a decisive role in Charlemagne's efforts to improve learning within his Empire.
Lastly, although the Classical learning that they preserved and disseminated was primarily from Ancient Greek, rather than Roman, authors, Muslim civilization made a major contribution to the access to Classical literature in Middle Ages.
So, again, while Charlemagne played a major role in helping to improve learning and preserve Latin literature in Europe, his efforts were far from the only ones that ensured the survival of Classical learning during the Middle Ages.