Nova Aetas

The Classical age, was dominated by several large civilizations before, very abruptly, coming to an end, after which humanity fell into a almost thousand year long dark age, losing a great deal of technology and great works of art and literature, in the process. Nova Aetas explores a scenario where at least in Europe, this great dark age is avoided, and instead the classical age lives on to survive and eventually be reborn without an age of darkness.

Point of Divergence
Emperor Aurelian avoids being murdered in 275, and goes on his campaign in the east, expanding the Roman Empire to a height unseen since the days of Trajan, and, more importantly bringing an earlier end to the crisis of the Third Century, without having by the reforms of Diocletian take place, and continuing the Principate.