I thought it was Irish monks who saved civilization by copying Greek and Roman scrolls during the Dark Ages. I guess it depends on which book you read.
The Irish Monks thing is true, but exaggerated. Also, the contribution of Muslim academics during the Middle Ages is exaggerated. Actually, the Byzantine Empire (the Eastern Roman Empire) did not fall until 1453 and preserved much of the Ancient texts.
Thomas Cahill, the author of "How the Irish Saved Civilization," also wrote "The Gifts of the Jews" and "Sailing the Wine-Dark Sea: Why the Greeks Matter." I think he's found a pretty good formula for publishing success -- find an ethnic group that a lot of Americans are proud to belong to, and tap into a ready-made audience.