The coalition has from 315 BCE to 311 BCE fought indecisively against Antigonus, who has shown himself energetic, resourceful, and imaginative, but unable to strike a decisive blow.

In view of this new threat from the East, Antigonus decides to make peace with all of his adversaries except Seleucus.

He orders Nicanor, one of his generals, to invade Babylonia from the east and his son Demetrius to attack it from the west, but they fail to oust Seleucus.

All the other Diadochi (Alexander's successors) confirm the existing boundaries and the freedom of the Greek cities.

Antigonus, no longer regent but merely strategos (officer in charge) of the whole of Asia, is to rule in Syria and from the Hellespont to the Euphrates, leaving Lysimachus with Thrace, Cassander with Greece and Macedonia (but only until Alexander IV comes of age in 305), and …

…Ptolemy with Egypt and Cyprus.

Ptolemy suppresses the island's kingdoms and in 310 forces the last king of Salamis, Nicocreon, to commit suicide, together with all his family. (For the next two and a half centuries, Cyprus will remain a Ptolemaic possession, ruled by a strategos, or governor-general.)

Ptolemy next attacks Cilicia, sparking the second coalition war (310-301) against Antigonus.

Defenders of the Argead dynasty have begun to declare, following the treaty, that Alexander IV should now exercise full power and that a regent is no longer needed.

The response of the Macedonian regent Cassander, his ruthlessness toward Alexander's family partly dictated by political considerations, is definitive: to secure his rule, in 310 BCE or 309 BCE, he commands the Macedonian general Glaucias to secretly assassinate Alexander IV and his mother Roxana.

The orders are carried out, and they are both poisoned.

The Middle East: 309–298 BCE

Linguistic and Cultural Shifts and the Babylonian War

The Babylonian War and the Rise of Seleucus

The Babylonian War (311–309 BCE) between Diadochi kings Antigonus I Monophthalmus and Seleucus I Nicator ends in a decisive victory for Seleucus. This conflict eliminates any chance of restoring Alexander's empire, a reality confirmed at the subsequent Battle of Ipsus. The outcome solidifies Seleucus's control over the eastern satrapies, marking the emergence of the extensive Seleucid Empire.

Evolution of the Old Persian Language

During the late fourth century BCE, the Old Persian language, known through inscriptions, clay tablets, and seals, transitions significantly. Inscriptions from the reigns of Artaxerxes II and Artaxerxes III evolve into a form of "pre-Middle Persian," setting the stage for Middle Persian and eventually New Persian, the foundation of modern Persian dialects. Recent discoveries in the Persepolis Fortification Archive at the Oriental Institute reveal practical administrative texts in Old Persian, highlighting broader use beyond royal ceremonial contexts.

The Babylonian War, a conflict fought from 311 BCE to 309 BCE between the Diadochi kings Antigonus I Monophthalmus and Seleucus I Nicator, ends in a victory for the latter.

The conflict ends any possibility of restoration of the empire of Alexander the Great, a result confirmed in the Battle of Ipsus.

It also marks the infancy of the Seleucid Empire by giving Seleucus control over the eastern satrapies of Alexander's former empire.