POD:Alexander The Great's best friend Hephaistion lives longer and inherits the Macedonian Empire.
Butterflies: Macedon destroys Rome after two devastating wars.
Macedon conquers and destroys Carthage in three wars parallel to OTL's Punic Wars.
During Hephaistion's reign, Macedon assumes dominance of the empire.
In the 100s AD, Egypt and Persia became independent.
During the 400s, Greece splits into city-states and the empire falls, though. Persia poses as Macedon's successor until its conquest by the Muslim Arabs.
Great King Craterus of the Macedonian Empire dissolves the Corinthian League and crushes the Greek revolts.
Great King Perdiccas of the Macedonian Empire is forced to make Persia autonomous and the lands east of the Tigris fall from his control.
The Etruscans dominate northern Italy.
The Crusades are in Greece and lead to Muslim domination of Greece for two centuries.