What happened on this land around c. 300–200 BCE (Hellenistic & Seleucid rule)?

Greek cities established; local Iranian resistance grows; rise of Parthians in northeast.
Rulers
Seleucid Empire
312–140 BCE
Successor state of Alexander’s empire, ruling over Iran and Mesopotamia.
Battles
Parthian Revolt
c. 250 BCE
Arsacid Parni tribes break from Seleucid rule.