The Selucids are far weaker, the Antigonids and Ptolemaics far stronger, they war. Antigonids fall to Celtic invasion by Brennus, while the Ptolemys conquer far further north. Julius Caesar arranges a marraige alliance with the Cleopatra you all know and love. Rome is far more focused on the east, what with the Bactrians, but since it has more manpower, it can still maintain the west, somewhat. Northern Europe is a tad bit more civilized, but still falls to Barbarian invaders. They set up their own little kingdoms. Recently, the Byzantine Emperor Valerian V tried to reconquer the West, but was defeated in the pivotal battle of the Lugdunum Plains, where the Visigothic warlord Hrodbert Thursson, in conjunction with the Franks and the Allemange, defeated him in pitched battle. Thursson went on to conquer a large Empire, though only a shard remains now, in Tolosia. The pink nation, btw, is one of his bastard son's kingdoms, who died pretty much at the point this map was made.
So basically, everywhere is in a dark age, and barbarians threaten from every direction. This is an NES where you can carve out a kingdom with a few thousand men and see it last into the modern age; this is the formative period of modern civilization. What fun.