Third Diadoch War

The Third Diadoch War (315/314-311/310 BC) was one of the wars between the generals of Alexander the Great for the redivision of the Macedonian Empire.

Background

After the Second Diadoch War, Antigonus Monophthalmus (one-eyed) became the most powerful military commander who conquered most of the Asian possessions of Alexander's empire. However, a coalition formed against him between the rulers of Macedonia Cassander, Egypt Ptolemy I Soter, Thrace Lysimachus, and the exiled satrap Seleucus.

The War

The beginning of the war was successful for Antigonus, as he captured Syria, Phoenicia, Caria, and Greece. However, a turning point in the course of the war was the Battle of Gaza, where Ptolemy I Soter defeated the army of Antigonus under the command of his son Demetrius.

The Turning Point

The victory at Gaza opened the way for Antigonus' enemies to go deep into his Asian possessions. Seleucus seized the moment and decided to regain power in Babylon. Ptolemy I Soter provided Seleucus with a thousand soldiers and 200 horsemen, with whom he went to Babylonia.

The Coalition Against Antigonus

Seleucus had found shelter with Ptolemy I Soter in Egypt, where it was easy for him to convince the Latida (a high-ranking official) of the danger posed by the increasing power of Antigon. Ptolemy I Soter also wanted to secure Syria, which he had already provisionally occupied in 318 BC and now controlled.

Ambassadors were sent to Cassander and Lysimachus, who were also concerned about the projects of Antigonus, and a coalition was formed between the three Diadochi. A ultimatum was launched to Antigonus, demanding a new distribution of the satrapies, which would mean dismantling his domain.

Outcome

The Third Diadoch War ultimately led to the defeat of Antigonus Monophthalmus and the fragmentation of his empire among his enemies. The war marked the beginning of a new era in the Macedonian Empire, with multiple powers vying for control.