Gian Biagio Conte, in his book Latin Literature: A History, argues that the fifty years of civil war commonly called 'the Crisis of the Third Century' politically broke apart the entire Roman-Mediterranean system, which hurled intellectuals to local metropolises rather than the imperial court in Italy. For example, African writers would be highly influenced by urban elites in Carthage, or Egyptian holy men would be highly influenced by academics in Alexandria. He explains this in terms of the persistence of Latin literature on the continent and in the western Mediterranean, and the revival of Greek literature in the eastern Mediterranean and in Anatolia. Let me know if you have any questions, this definitely was a broad answer.

I asked a [ similar question ] ( http://www.reddit.com/r/AskHistorians/comments/38fc2p/whenhow_did_a_greek_identity_emerge_from_the/ ) not too long ago, you may find some of the answers there interesting.