The hidden Renaissance

Many recall the Renaissance almost stillborn by the Bubonic Plague. The Crusades fostered immense ill will and destruction, but in their wake came great knowledge.
The Arabs and Byzantines preserved many ancient texts, mostly Greek in origin, but some few from Latin authors.

There was another Renaissance ... from the west. Charlemagne, although illiterate was able to appreciate learning. As a point of irony, the Romans considered the land that respread latin culture so marginal, it was not worth conquering. That land is what we now call Ireland...

From the sixth to well beyond the eleventh century, wandering Irish monks spread knowlege wherever their travels took them. This was crucial for when their mission began they were wandering through a 'desert' bereft of any civilizing influence such as what the Roman system of values and administration had provided for the better part of a millenium. Without that Roman influence, religion, in this case, Celtic Christianity, filled the gap.

Christianity was forged in a Red revolution, one of blood and persecution.

It spread through a green revolution, one in which anchorites found the most inhospitable territory or people and spread the word of God.

There was a third, the white revolution. In a land completely lacking existing population centers, the traditional diocessian and bishopric set up that the Ecumene, or Roman world adopted would not work in Ireland. The monestaries became their villages and towns... Armagh, Kildare, Kells, the names ring down through the centuries.

On top of serving as a rallying point for population centers to form, the monks in ireland spread literacy as well, connecting themselves to a literary tradition that stretched back a millenium or more. In doing so, they created the first vernacular language in all of Europe. In time, after the Barbarians had laid waste to the western world, Europe would be reconnected to its own past, spared from Moslem conquest, and inspired each ethnic group to develop its own vernacular language and literary works.

The Franks would have nothing more than a bunch of Animists, without anything other than their own traditions, much less anything to connect them with the rest of Europe. How the Irish Saved Civilization and Civilization by Thomas Cahill and Kenneth Clark respectively, are excellent resources on this.