Alexander the Great: From Pella to Babylon, 356–323 BCE

On the evening of June 11, 323 BCE, a thirty-two-year-old king lay dying of fever in the palace of Nebuchadnezzar II in Babylon. He had crossed the Hellespont into Asia eleven years earlier with about 37,000 men and a personal copy of the Iliad. He had not lost a battle since. His empire, at its greatest extent, ran from the western Adriatic to the Indus River — roughly five million square kilometres, the largest political unit the world had ever seen. He had founded perhaps twenty cities and named most of them Alexandria. He left no clear successor and no functional plan of succession. When his generals asked, as classical sources record, “to whom do you leave your kingdom,” he is said to have replied “to the strongest.” Within twenty-two years his empire had broken into the four successor kingdoms — Macedonia, Ptolemaic Egypt, the Seleucid Empire, and the kingdom of Pergamon — that would dominate the eastern Mediterranean and Near East for the next three centuries. His name was Alexander III of Macedon.

Macedon Before Alexander

Alexander’s father, Philip II (r. 359–336 BCE), is the figure most often left out of popular accounts. Philip transformed Macedon — a backwater of the Greek world at his accession — into the dominant military power of the Aegean. He restructured the Macedonian army around the long sarissa-armed phalanx, integrated cavalry into combined-arms tactics, professionalised the officer corps, and over twenty years subdued or allied with most of mainland Greece. His victory over the combined forces of Athens and Thebes at Chaeronea on August 2, 338 BCE — where the eighteen-year-old Alexander commanded the Macedonian left wing — established Macedonian hegemony over the Greek city-states.

Philip was preparing an invasion of Achaemenid Persia when he was assassinated in October 336 BCE at the wedding of his daughter Cleopatra to Alexander I of Epirus. The assassin, his own bodyguard Pausanias of Orestis, was killed on the spot. The political background remains disputed — some ancient sources, and several modern historians (including A. B. Bosworth), have suspected Olympias, Alexander, or the Persian court of orchestration. Alexander succeeded directly at age 20, secured his throne by executing potential rivals, and inherited Philip’s planned Asian campaign.

Aristotle and the Education

From roughly 343 to 340 BCE, Philip employed the philosopher Aristotle as Alexander’s tutor at the small Macedonian town of Mieza. The relationship is one of the most documented teacher-pupil pairs in classical history. Aristotle taught Alexander Greek literature, philosophy, geography, biology, medicine, and political theory; Alexander reportedly sent Aristotle specimens of plants and animals from his Asian campaigns. The annotated Iliad that Alexander carried throughout his expedition was a gift from Aristotle. The historian Plutarch, writing four centuries later, gave this education substantial credit for Alexander’s literary self-fashioning — his constant comparisons of himself to Achilles, his patronage of Greek artists and writers, his desire to be remembered.

The Asian Campaign: 334–323 BCE

Alexander crossed the Hellespont in May 334 BCE. His first major engagement, at the Granicus River the same month, defeated a Persian satrapal army and opened Asia Minor. By autumn he had taken Sardis, freed the Greek cities of Ionia from Persian control, and was campaigning south through Caria and Lycia.

The first encounter with the Persian Great King himself, Darius III, came at the Battle of Issus on November 5, 333 BCE, in a narrow coastal plain in northern Syria. Alexander’s tactically brilliant cavalry charge through the Persian centre forced Darius to flee the field; Alexander captured Darius’s mother, wife, and children, who would travel with him for the next several years and whom he treated, by all accounts, with conspicuous courtesy. Darius offered Alexander a substantial ransom and the western half of his empire; Alexander refused.

The siege of Tyre — the great Phoenician city on a rocky island half a kilometre offshore — lasted seven months, from January to July 332 BCE, and ended in the construction of a massive causeway and the storming of the walls. Tyre’s male population was killed; its women and children sold into slavery. Gaza fell shortly after; Egypt welcomed Alexander as liberator from Persian rule. He founded the first Alexandria in the Nile Delta in 331 BCE, visited the oracle of the Egyptian-Libyan god Ammon at Siwa Oasis, where (according to several sources) he was greeted as son of the god, and resumed his march east.

The decisive engagement was the Battle of Gaugamela on October 1, 331 BCE, on a plain east of modern Mosul. Darius had assembled what was probably the largest army the Achaemenid Empire could field — modern estimates run from 50,000 to 100,000 men, including scythed chariots and war elephants — against Alexander’s roughly 47,000. Alexander’s wedge-shaped charge directly at Darius’s command position, exploiting a gap in the Persian line, forced Darius from the field a second time. The battle effectively ended Achaemenid rule. Alexander entered Babylon unopposed, then Susa, then Persepolis (where the great palace was burned in May 330 BCE — whether deliberately or in a drunken party is contested by sources), then Ecbatana. Darius III was killed by his own satrap Bessus of Bactria in July 330 BCE while fleeing east; Alexander, who had pursued him for months, ordered Darius’s body returned to Persepolis with royal honours.

The eastern campaigns that followed — through Bactria and Sogdiana (modern Afghanistan and Uzbekistan) from 329 to 327 BCE, and into India in 326 BCE — were harder. The Bactrian and Sogdian terrain favoured guerrilla warfare; the campaigns took two years to subdue. Alexander married Roxana, the daughter of a Sogdian noble, in 327 BCE — politically a unification of conqueror and conquered. The same year, he introduced the Persian court ceremony of proskynesis (prostration) at his own court, to the open contempt of his Macedonian veterans; the resulting tensions produced several conspiracies against his life and the execution of his official historian Callisthenes (Aristotle’s nephew).

In 326 BCE Alexander crossed the Indus into the Punjab and won his last major battle, against the Indian king Porus at the Hydaspes River in May 326 BCE. He intended to push on to the Ganges. His army, however, after eight years of continuous campaigning, refused. At the Hyphasis River in late 326 BCE — the easternmost point of his march — his men staged a sit-down protest. Alexander, after three days of arguments, agreed to turn back. The return through the Gedrosian Desert (modern Makran, in southern Pakistan) in 325 BCE was disastrous; an estimated three-quarters of the marching army died of thirst and exposure. Alexander reached Babylon in 324 BCE.

Babylon, 323 BCE

Alexander spent the last year of his life in Babylon, planning the next phase — an Arabian expedition, a deepwater fleet for the Persian Gulf, the rebuilding of the city as his imperial capital, and an unspecified western campaign possibly aimed at Carthage. In late May 323 BCE, after attending a series of banquets at the house of his admiral Nearchus and the Thessalian Medius of Larissa, he developed a fever. The fever worsened over twelve days. By the morning of June 10 he could no longer speak. He died on the evening of June 10 or 11. He was 32 years old.

The cause of death has been disputed for 2,300 years. Ancient sources mention poisoning theories (Antipater and his sons, the future regent Cassander, are most often named); modern medical analysts, working from the contemporary descriptions in Arrian and Plutarch, have offered diagnoses including Plasmodium falciparum malaria (Eugene Borza, 2004), typhoid fever (David Oldach et al., 1998), West Nile encephalitis (John Marr and Charles Calisher, 2003), pancreatitis from his heavy drinking, and acute Guillain-Barré syndrome (Katherine Hall, 2018, in The Ancient History Bulletin). No theory has produced a scholarly consensus.

Alexander’s body was preserved in honey or wax, escorted in a magnificent carriage toward Macedonia for burial, hijacked en route by his general Ptolemy in late 322 BCE, and taken to Memphis and then Alexandria, where the tomb (the Sēma) became a major political shrine. The Roman emperor Augustus visited the tomb in 30 BCE; the emperor Caracalla in 215 CE was the last documented visitor. The tomb has been lost since late antiquity. Multiple modern archaeological searches in Alexandria have not located it.

What Most Accounts Get Wrong

Three corrections. The first is the elision of Philip II. Philip built the army Alexander used, broke the Greek city-states for the campaign Alexander conducted, and planned the Persian invasion Alexander executed. Without Philip’s twenty years of work, there would have been no Alexander campaign.

The second is the moral framing. Ancient and modern admirers tend to focus on Alexander’s military brilliance, cultural patronage, and reputed personal courage, all of which were real. The campaigns also involved the destruction of Tyre, the massacre of the male population of Gaza, the burning of Persepolis, the executions of his officers Parmenion and Philotas on conspiracy charges, the killing of his close friend Cleitus the Black in a drunken quarrel in 328 BCE, the execution of Callisthenes, and the deaths of perhaps three-quarters of the army on the Gedrosian march — most of which his admirers find more difficult to discuss. The picture is mixed.

The third is the question of his cultural legacy. The “Hellenisation” of the eastern Mediterranean and western Asia was real but uneven: it produced the Greek-speaking ruling classes of the Hellenistic kingdoms, several centuries of major scientific work at the Library of Alexandria, the Septuagint translation of the Hebrew Bible into Greek, and the cultural conditions for the eventual spread of early Christianity in Greek. It did not, however, displace the local languages, religions, and institutions of the conquered regions, most of which persisted under Macedonian and then Roman rule and re-emerged when the Hellenistic kingdoms fell.

Why It Still Matters

Alexander’s campaign is the founding event of the Hellenistic Age — the three centuries between his death in 323 BCE and the Roman annexation of Ptolemaic Egypt in 30 BCE — and one of the foundational events of the cultural history of the Mediterranean and Near East. The Greek-speaking, Macedonian-ruled kingdoms he left behind shaped the linguistic, religious, scientific, and political environment in which Roman imperialism, Second Temple Judaism, and (later) early Christianity emerged. His personal example — both as inspiration and as cautionary tale — has been claimed by everyone from Julius Caesar (who reportedly wept at Alexander’s statue in Cadiz because at the same age Alexander had conquered the world) to Napoleon to twentieth-century military theorists. The historical Alexander, beneath the legendry, is recoverable in the surviving Roman-era sources (Arrian, Plutarch, Diodorus Siculus, Quintus Curtius Rufus, Justin) which themselves draw on the now-lost contemporary accounts of his companion Ptolemy and the engineer Aristobulus.

For more on the ancient world, see our pieces on Babylon and ancient Egypt.

Frequently Asked Questions

Who was Alexander the Great?

Alexander III of Macedon (356–323 BCE) was the king of Macedon from 336 BCE until his death, and the conqueror of the Achaemenid Persian Empire. Between 334 and 323 BCE he built the largest empire the world had yet seen — running from the Adriatic Sea to the Indus River — and founded perhaps twenty cities, most of them named Alexandria. He died of fever at Babylon at age 32 and was succeeded by no single ruler.

Was Aristotle really Alexander’s tutor?

Yes. Philip II of Macedon employed Aristotle as Alexander’s tutor at the school of Mieza outside Pella from approximately 343 to 340 BCE. Aristotle taught Alexander Greek literature, philosophy, geography, biology, and political theory. The annotated copy of the Iliad that Alexander reportedly carried throughout his campaigns was a gift from Aristotle. The relationship is documented in Plutarch’s Life of Alexander and other ancient sources.

How did Alexander defeat the Persians?

Through four major pitched battles in eleven years. At the Granicus River in May 334 BCE he defeated a Persian satrapal army; at Issus in November 333 BCE and at Gaugamela on October 1, 331 BCE he defeated the army of Darius III himself; at the Hydaspes in May 326 BCE he defeated the Indian king Porus. Tactically, his combined-arms use of the long-sarissa Macedonian phalanx as an anvil and his heavy Companion Cavalry as a hammer, combined with personal command from the front, repeatedly broke larger but less well-coordinated Persian forces.

How far east did Alexander go?

The easternmost point of Alexander’s advance was the Hyphasis River, modern Beas, in Indian Punjab, reached in late 326 BCE. There his army staged a sit-down protest refusing to march further east toward the Ganges; Alexander, after three days of arguments with his troops, agreed to turn back. The return through the Gedrosian Desert in 325 BCE killed perhaps three-quarters of the marching army.

How did Alexander die?

Alexander died of fever at Babylon on June 10 or 11, 323 BCE, aged 32, after a twelve-day illness following heavy drinking at banquets in his honour. The precise cause has been disputed since antiquity; ancient sources mention possible poisoning, and modern medical analyses have proposed malaria (Plasmodium falciparum), typhoid, West Nile encephalitis, pancreatitis, and Guillain-Barré syndrome. No consensus has emerged.

What happened to Alexander’s empire?

Alexander left no clear successor. His empire fragmented during the Wars of the Diadochi (323–281 BCE) among his former generals, ultimately producing four major Hellenistic kingdoms: Macedon under the Antigonid dynasty, Ptolemaic Egypt under Ptolemy I and his successors, the Seleucid Empire under Seleucus I and his successors (covering most of the former Persian territories), and Pergamon under the Attalid dynasty (in western Asia Minor). The Hellenistic Age these kingdoms inaugurated lasted until the Roman annexation of Egypt in 30 BCE.

Sources

1. British Museum — Hellenistic and Greek collections
2. Arrian (trans. Aubrey de Sélincourt), The Campaigns of Alexander (Penguin Classics, 1971)
3. Plutarch (trans. Ian Scott-Kilvert), “Life of Alexander,” in The Age of Alexander (Penguin Classics, 1973)
4. A. B. Bosworth, Conquest and Empire: The Reign of Alexander the Great (Cambridge University Press, 1988)
5. Robin Lane Fox, Alexander the Great (Allen Lane, 1973)
6. Peter Green, Alexander of Macedon, 356–323 B.C.: A Historical Biography (University of California Press, 1991)
7. Pierre Briant, From Cyrus to Alexander: A History of the Persian Empire (Eisenbrauns, 2002)
8. Paul Cartledge, Alexander the Great: The Hunt for a New Past (Macmillan, 2004)
9. Hans-Joachim Gehrke, Alexander der Große (C. H. Beck, 1996)