Wars of the Diadochi (322-281 BC): Alexander's Generals at War

The Wars of the Diadochi were a series of conflicts fought between 322 and 281 BC among the generals of Alexander the Great over control of his empire. “Diadochi” means “successors” in Greek. Over four decades of shifting alliances, battles and murders, the empire that stretched from Greece to India broke apart into rival kingdoms that shaped the Hellenistic world for three centuries.

Background: an empire without a ruler

When Alexander died in Babylon in June 323 BC, he left no adult heir (see the death of Alexander the Great). His generals agreed to share power in the name of two kings: his half-brother Philip III Arrhidaeus and his infant son Alexander IV. Perdiccas became regent, and the provinces were divided among the leading officers.

The arrangement depended on trust that did not exist. Each general controlled troops and treasure, and each had reason to fear that the others would grow too strong. The kings themselves were powerless pawns.

The main sources for these years are Diodorus Siculus, whose Books 18 to 20 draw on the lost history of Hieronymus of Cardia, a participant who served Eumenes, Antigonus and Demetrius in turn, and Plutarch’s biographies of Eumenes and Demetrius. Babylonian chronicles and cuneiform documents add dates for events in Mesopotamia. Because the narrative of Diodorus breaks off after 302 BC, the later stages of the wars are known in much less detail.

The First War (322–320 BC)

Tension came to a head when Perdiccas appeared to aim at the throne, planning to marry Alexander’s sister Cleopatra. Antipater, the regent in Macedonia, Craterus and Antigonus allied against him, joined by Ptolemy I Soter, who had seized Alexander’s body in 321 BC and taken it to Egypt.

Perdiccas invaded Egypt but failed to cross the Nile near Memphis, losing many men to drowning and crocodiles. His own officers, among them Seleucus, murdered him in 320 BC. Meanwhile his ally Eumenes defeated and killed Craterus in Asia Minor.

At the conference of Triparadisus in Syria, Antipater became regent and the provinces were redistributed. Seleucus received Babylonia, and Antigonus was given command of the royal army in Asia.

The Second War (318–316 BC)

Antipater died in 319 BC, naming the old general Polyperchon as regent instead of his own son Cassander. Cassander allied with Antigonus and Ptolemy against Polyperchon. Alexander’s mother Olympias backed Polyperchon, had Philip III and his wife killed in 317 BC, and was herself executed by Cassander in 316 BC.

In Asia, Eumenes, a Greek from Cardia and loyal to Alexander’s family, fought Antigonus in two great battles in Iran, at Paraitakene in 317 BC and Gabiene in the winter of 316/315 BC. After Gabiene, the veteran Macedonian unit known as the Silver Shields handed Eumenes over to Antigonus in exchange for their captured baggage, and he was executed.

The Third War and the Babylonian War (314–309 BC)

Antigonus was now master of most of Asia, and the other successors united against him. Seleucus had fled Babylon to Ptolemy. In 312 BC Ptolemy and Seleucus defeated Antigonus’ son Demetrius at the Battle of Gaza, and Seleucus returned to Babylon with a small force. This return later marked the start of the Seleucid era, a calendar used in the Near East for centuries.

A general peace in 311 BC recognised the existing positions, but Seleucus and Antigonus continued fighting in the Babylonian War until about 309 BC, when Seleucus secured Mesopotamia and the east. Around 310 BC Cassander secretly had Roxana and the young Alexander IV killed, ending Alexander’s line as kings.

The Fourth War and Ipsus (308–301 BC)

Demetrius captured Athens in 307 BC and in 306 BC destroyed Ptolemy’s fleet at Salamis in Cyprus. After this victory Antigonus and Demetrius took the title of king, and Ptolemy, Seleucus, Cassander and Lysimachus soon did the same. The empire was now openly divided into kingdoms.

Antigonus failed to invade Egypt in 306 BC, and Demetrius failed to take Rhodes in a famous year-long siege (see the Siege of Rhodes). In 301 BC Seleucus, fresh from a treaty with the Indian ruler Chandragupta Maurya that gave him several hundred war elephants, joined Lysimachus in central Asia Minor. At the Battle of Ipsus the elephants helped cut off Demetrius’ cavalry, and Antigonus, then over 80 years old, was killed.

The final struggles (301–281 BC)

The victors divided Antigonus’ lands. Demetrius survived, became king of Macedonia in 294 BC and lost it again in 288 BC, dying as Seleucus’ prisoner in 283 BC. Lysimachus built a large kingdom in Thrace and Asia Minor.

In 281 BC Seleucus defeated and killed Lysimachus at the Battle of Corupedium in Lydia. He crossed into Europe to claim Macedonia, but was murdered near Lysimachia by Ptolemy Keraunos, a disinherited son of Ptolemy I. Seleucus was the last of Alexander’s generals; with his death the age of the Diadochi ended.

Key people

• Antigonus I Monophthalmus (“the One-Eyed”, c. 382–301 BC): The most powerful successor, killed at Ipsus.
• Ptolemy I Soter (c. 367–282 BC): Ruler of Egypt and founder of the Ptolemaic dynasty.
• Seleucus I Nicator (c. 358–281 BC): Founder of the Seleucid Empire.
• Cassander (c. 355–297 BC): Son of Antipater and ruler of Macedonia.
• Lysimachus (c. 360–281 BC): Ruler of Thrace and later much of Asia Minor.
• Demetrius Poliorcetes (c. 337–283 BC): Son of Antigonus, brilliant but reckless commander, briefly king of Macedonia.
• Perdiccas (died 320 BC): Regent after Alexander’s death, killed by his own officers in Egypt.
• Eumenes of Cardia (c. 362–316 BC): Greek secretary turned general, loyal to the royal family.

Timeline

• 323 BC, June: Alexander dies; the Settlement of Babylon divides the provinces.
• 320 BC: Perdiccas is murdered in Egypt; the Triparadisus conference follows.
• 317 BC: Olympias has Philip III killed.
• 316/315 BC, winter: Battle of Gabiene; Eumenes is betrayed and executed.
• 312 BC: Battle of Gaza; Seleucus returns to Babylon.
• c. 310 BC: Roxana and Alexander IV are murdered.
• 306 BC: Antigonus and Demetrius proclaim themselves kings.
• 301 BC: Battle of Ipsus; Antigonus is killed.
• 281 BC: Battle of Corupedium; Seleucus is murdered soon afterwards.

Consequences

By the end of the wars, three major dynasties had emerged. The Ptolemies ruled Egypt until 30 BC. The Seleucids held Syria, Mesopotamia and Iran, slowly losing ground to the Parthians and Rome. The Antigonids, descended from Antigonus and Demetrius, secured Macedonia from about 276 BC until the Roman conquest in 168 BC.

The wars also changed warfare and kingship. Armies grew larger and used elephants, giant siege engines and huge warships. Kings presented themselves as heirs of Alexander, founded Greek cities across Asia and competed as patrons of art and learning.

The human cost was high. Cities changed hands repeatedly, armies lived off the land, and whole populations were moved to found new settlements. Yet the period also saw remarkable building: Alexandria grew into a great capital, Seleucus founded Antioch and Seleucia on the Tigris, and Lysimachus and Cassander founded new cities such as Lysimachia and Thessalonica.

Historians long saw the Diadochi as selfish adventurers who destroyed Alexander’s legacy. Many now stress instead that they had little choice: with no strong heir, no single general could command the loyalty of all the armies, and division was perhaps unavoidable.

Why it matters

The Wars of the Diadochi decided that Alexander’s empire would not survive as a single state. The kingdoms they created spread Greek language and culture from the Mediterranean to Central Asia, forming the Hellenistic world that Rome would later inherit.