Why did Alexander the Great's empire fall?
Why did Alexander the Great's empire fall? (click headline for original source)
It’s a really big mess. Dramatic though.
The following was spread out across more than a dozen Wikipedia articles, and I’ve drawn together what I can to form this comprehensive and long summary.
In short: Lots of fighting between generals resulted in three of them claiming empires in Asia, Greece and Egypt. All of these later fell to the expanding Romans.
In long:
Alexander, the military genius who conquered all the land from Greece to India in a decade without ever losing a battle, suddenly died in June 323 BCE. He was only 32 and had no children (yet - his wife Roxana would give birth after his death), and had made plans to invade Arabia and set up his capital at Babylon - plans which would never be put into effect.
No one knows for sure if he got sick or was poisoned; it could have been either.
Regardless, his generals immediately began fighting over who should take the throne. The infantry, under Meleager, said that Alexander’s half-brother should become king; the cavalry, under Perdiccas, supported waiting until Roxana’s child was born and, assuming it was male, could take the throne.
After a lot of arguing, they settled on the joint kingship (in name only, with no real power) of Phillip III (Alexander’s mentally ill half-brother) and the child, who turned out to be a male, Alexander IV. Perdiccas became the regent (the real ruler) of the entire empire, with Meleager as his lieutenant.
Soon, though, things started to go sour. Perdiccas had Meleager and the other infantry generals murdered, assuming full control. He divided up the empire among his loyal cavalry generals, making them each ‘satraps’ (a Persian version of provincial governor) over their areas, while still maintaining authority over them.
Various generals began trying to court Alexander’s sister, Cleopatra of Macedonia, in an attempt to gain influence with the Macedonians. The first of these was Leonnatus, satrap of “Hellespontine Phrygia” in northwestern Anatolia.
Meanwhile, revolts popped up all over the empire as Alexander’s subjects found out he was dead. The biggest of these was in Greece, and a bunch of city-states rallied together against its joint rulers, Craterus and Antipater, and besieged Antipater in the fortress of Lamia. Leonnatus went with his army to relieve Antipater and did so successfully, putting down the rebellion; however, Leonnatus was killed in action.
This left Cleopatra relatively open; her mother offered her to Perdiccas, who eagerly accepted, as it would make him a successor of Alexander instead of just a regent. He had been planning to marry Antipater’s daughter, but ditched that in favor of the more important wedding, so Antipater was a little ticked.
One of the other revolts was in Cappadocia (central Anatolia), where the satrap Eumenes was supposed to be in control. Eumenes needed help, and the closest was Antigonus, who ruled western Anatolia; however, since Leonnatus had gone to Greece, Antigonus felt he couldn’t take Cappadocia without help, so he refused to join at all.
Craterus, meanwhile, was upset that, despite being one of Alexander’s most important generals during the wars, he kind of got overlooked by Perdiccas.
After Perdiccas married Cleopatra, Antipater, Antigonus, and Craterus formed a coalition and rebelled against Perdiccas, allying themselves with Ptolemy. Perdiccas left that up to Eumenes to deal with and continued with his army into Egypt.
Ptolemy’s army inflicted a sound defeat on Perdiccas’s, who was humiliated, and during the night his top subordinates Peithon and Antigenes (and maybe Seleucus, it’s unsure) murdered him in his tent. Meanwhile, Craterus fell in battle in Anatolia when his “charging horse fell over him”.
So, to recap up to this point: Antigonus and Antipater are fighting Eumenes in Anatolia, and Ptolemy just beat Perdiccas out of Egypt; Perdiccas was then assassinated by Seleucus (maybe), Peithon and Antigenes.
With Perdiccas dead, his assassins negotiated with Ptolemy to give Ptolemy the regency in return for satrapies, but Ptolemy declined, preferring to hold on to his power base rather than try recklessly to take over like Perdiccas had.
Ptolemy suggested Peithon and Arrhidaeus (the guy who moved the body of Alexander for Ptolemy earlier), for joint regents. In a meeting in 321 BCE Eurydice, the wife of Phillip III (crazy brother king guy), opposed that strongly and the generals agreed that Antipater would be regent instead. They again divided up the empire into satraps.
In addition, the generals at this meeting assigned Eumenes a death penalty for joining with Perdiccas (remember, these were the guys that rebelled against and killed Perdiccas), trusting Antigonus and Antipater with his execution. Eumenes was betrayed by his own troops, but fled to a fortress called Nora before the enemies could get to him. He held out there for a year, and then…things got even more messy.
Antipater, who had left the war against Eumenes to Antigonus and gone back to Macedonia, was suddenly afflicted with a terrible illness and died. He left the regency, not to his son Cassander, but to his friend Polyperchon, former second-in-command to Craterus (the guy whose horse fell on him).
Cassander (who was very ambitious, which may be why Antipater didn’t give him the regency) went to Ptolemy and Antigonus for help in dethroning Polyperchon, and Polyperchon got Eumenes on his side. Meanwhile Peithon (assassin of Perdiccas who was rejected for the regency) started expanding in the eastern satrapies, and Seleucus fought to maintain control of Babylon (which he’d been given in the recent partition), which was rebelling.
So, right now we have Cassander fighting Polyperchon in Greece, allied with Antigonus, who is invading Anatolia to beat up Eumenes, who is allied with Polyperchon; in addition, Peithon is rising up in the east and Seleucus is gaining power in Babylon. (During all of this, Ptolemy was allied with Antigonus and Cassander, but mostly tried to stay in control of his lands.)
Polyperchon was initially successful in Greece, but Cassander soon destroyed his fleet and took Athens, then Macedon, seizing control of the disabled King Phillip III and his wife Eurydice. Polyperchon ran to Epirus (Albania/Greece), joining Alexander’s mom Olympia, his widow Roxana, and the infant king Alexander IV.
Now Olympia and Polyperchon led an army into Macedon to take it back from Cassander. The Macedonians refused to fight against Alexander’s mom, so it was easy to take back. Phillip III and Eurydice escaped but were later captured, and Olympia had Phillip III put to death in order to remove him as a tool against her. Eurydice was forced to commit suicide by Olympia.
Meanwhile, over in the east, a bunch of satrapies united under a guy named Peucestas (satrap of Persis, southern Iran) to defeat Peithon, but didn’t pursue him to kill him. Peithon and Seleucus (Babylon guy) allied with the invading Antigonus. Peucestas was an ally of Eumenes, and the two fought Antigonus decisively at Paraitacene; however, either because Peucestas was an idiot or had some other motive, he left Eumenes’ baggage camp in the open, and Antigonus grabbed it quickly.
The baggage camp contained not only the loots of the Silver Shields, Macedon’s most decorated veterans, but also their wives and children. When Antigonus offered the loot back to the Silver Shields in exchange for Eumenes, they readily accepted, and Antigonus executed Eumenes and took over Peucestas’s satrap, effectively throwing him into captivity.
Right after this, hungry Peithon tried to incite a revolt against Antigonus, who had him executed and took over his land. Antigonus traveled to Babylon, where he was welcomed by Seleucus, but a little bit later Seleucus punished one of Antigonus’s officers without asking him first, which made him angry, and long story short Seleucus ran to Egypt to seek help from Ptolemy.
Cassander took this opportunity to have Roxana and the infant king poisoned, as well as marrying Alexander’s half-sister Thessalonica. He was in a pretty good position to declare himself king.
Except Antigonus. By now, Antigonus was easily the most powerful of the remaining kings, and he controlled all of the Asian satrapies. As a result, Seleucus, Ptolemy, Cassander and Lysimachus (king of Thracia) united against Antigonus, partly through marriage and partly just because they all bordered him.
At some point, Polyperchon gave up the regency to Antigonus, hoping to ally with him. Antigonus sent Heracles, a supposed illegitimate child of Alexander, to Polyperchon to give him a bargaining chip against Cassander, but Cassander bribed Polyperchon to murder him. This left Cassander (married to Alexander’s half-sister) the only guy with any connection to Alexander, and he declared himself king.
There’s some contradicting information in the articles here, but suffice it to say that Antigonus and Ptolemy invaded each other a lot.
Antigonus’s son Demetrius beat Ptolemy in the Battle of Salamis, utterly destroying his navy; he then went to Greece as a liberator and ruled Athens. However, due to his nasty habit of “seeking favor” of young boys (as Wikipedia puts it), he soon became quite unpopular and his dad had to call him back to Asia. (One of those young boys even threw himself into a pot of scalding water to avoid, you know.)
Now Seleucus and Lysimachus began a joint invasion of the Middle East, and defeated Antigonus and his son at the Battle of Ipsus in 301 BCE. Antigonus was 81 years old.
Seleucus and Lysimachus divided up Asia, but Demetrius got to Lysimachus’s territory with an army and ravaged it. Soon after, Cassander died in 297 and Demetrius was able to murder Cassander’s son and take over Macedon.
This finally leaves us with the three empires that Alexander’s empire disintegrated into: the Seleucids, in Asia; the Antigonids, in Greece; and the Ptolemaic empire in Egypt.
