Who was Alexander the Great?
In twelve years a twenty-year-old conquered the known world — and fused it. The first globalization had a name: Alexander.
Last updated: October 2026
He was twenty when he took the throne and thirty-two when he died in Babylon. In between, Alexander of Macedon conquered more of the earth than any man before him — and in doing so stitched East to West into a single connected world for the first time in history.
Alexander was born in 356 BCE in Pella, the capital of Macedon, a rugged kingdom on the northern edge of the Greek world. His father, Philip II, had turned Macedon from a frontier state into the dominant military power of Greece. His mother, Olympias, came from Epirus and gave her son a fierce sense of destiny. As a boy Alexander was taught by Aristotle, the philosopher Philip summoned to tutor the prince, who grounded him in philosophy, science, medicine, and the poetry of Homer. Alexander is said to have carried a copy of the Iliad under his pillow, and to have measured himself against Achilles, the hero of that epic. The lesson stuck: he grew up believing that glory was won, not inherited.
Philip rebuilt the Macedonian army around a new weapon, the sarissa, a pike far longer than the spears of a traditional Greek phalanx, and around disciplined cavalry that struck where the pike line had pinned the enemy. Alexander learned this system from inside it. At the Battle of Chaeronea in 338 BCE, still in his teens, he commanded the Macedonian left wing and helped crush an alliance of Greek city-states, ending their independence in practice. Two years later Philip was assassinated at a wedding feast, and the twenty-year-old Alexander inherited a kingdom, an army, and his father’s unfinished plan: an invasion of the Persian Empire, the superpower of the age.
His first task was survival. Rivals at court, restless Greek cities, and revolts on the northern frontier all tested him at once. He moved fast, secured the throne, and made an example of Thebes, which rebelled in 335 BCE: the city was destroyed, a warning the other Greek states understood. Then he crossed into Asia in 334 BCE with an army of roughly forty thousand men, a force far smaller than the empire he intended to conquer. What it lacked in numbers it made up for in training, cohesion, and a commander who led from the front of the cavalry charge, again and again, at personal risk.
The conquest of Persia unfolded as a sequence of great set-piece battles, each one won by the same formula: the Macedonian phalanx held the Persian centre while Alexander’s companion cavalry found a gap and drove at the enemy commander. At the Granicus in 334 BCE he forced a river crossing against Persian satraps. At Issus in 333 BCE he defeated King Darius III himself, who fled the field, leaving his camp, his baggage, and his family behind. Alexander treated Darius’s captured family with respect, a gesture that became part of his legend. He then turned south, taking the great port cities of the Levant, and endured a long siege at Tyre in 332 BCE, an island fortress that fell only after his engineers built a causeway out to it.
In Egypt he was welcomed rather than resisted. He founded the city of Alexandria at the mouth of the Nile in 331 BCE, the first of many cities he would name after himself, and visited the oracle of the god Amun at Siwa, where, according to tradition, he was hailed as the son of the god. Then he turned back east for the decisive battle. At Gaugamela in 331 BCE, on a wide plain chosen by Darius for his chariots and his far larger army, Alexander’s cavalry struck the gap that opened when the Persian line stretched to outflank him. Darius fled again. Babylon and Susa opened their gates, and at Persepolis, the ceremonial heart of the Persian Empire, Alexander’s army took the royal treasury and later burned the palace, an act ancient writers variously blamed on revenge, drunkenness, or deliberate policy.
Darius was murdered by his own officers in 330 BCE while fleeing east. Alexander, who had chased him across the mountains, gave his enemy a royal burial. It was a political act as much as a generous one: by honouring Darius, Alexander presented himself not as a foreign destroyer but as the legitimate successor to the Persian throne. He began to wear Persian dress on formal occasions, to keep Persian officials in his administration, and to marry into the Persian nobility. Many of his Macedonian veterans resented it. To them, they had conquered Persia; to Alexander, he had inherited it.
The eastern campaigns were the hardest part of the conquest. In Bactria and Sogdiana, in what is now Afghanistan and Central Asia, Alexander faced guerrilla resistance in mountain valleys, where fortresses had to be taken one by one. He married Roxana, a Bactrian noblewoman, binding a local dynasty to his own. He founded more Alexandrias, garrison towns that would anchor Greek culture deep in Asia for centuries. He also grew more absolute, and more feared. The killing of his friend Cleitus in a drunken quarrel, and the execution of the court historian Callisthenes after a conspiracy of pages, darkened his reputation even among admirers. Conquest, by now, was also a purge.
In 326 BCE he crossed into India and met King Porus at the Hydaspes River, winning a hard battle fought in monsoon rain against war elephants, a weapon his men had never faced. He kept Porus as a subordinate king, a pattern of ruling through local rulers that he repeated across the empire. But at the Hyphasis River, his army refused to go further. The men had marched for eight years, they had heard of still greater kingdoms ahead, and they would not march into the unknown. Alexander sulked in his tent for days, according to the sources, then turned back. It was the only defeat he ever suffered, and it came from his own soldiers.
The return journey was brutal. Alexander led part of the army through the Gedrosian desert, in what is now southern Pakistan and Iran, where heat and thirst killed thousands. By the time he reached Babylon in 324 BCE, he was planning again: a fleet to Arabia, new cities, new campaigns. His body, worn by a dozen wounds, years of campaigning, and heavy drinking, was failing. In 323 BCE, after days of fever in Babylon, he died at the age of thirty-two. The cause has been debated ever since, with modern writers suggesting malaria, typhoid, poisoning, or alcohol-related illness. No explanation is certain, and the ancient sources themselves disagree.
Alexander’s lasting project was not only conquest but fusion. At Susa in 324 BCE he staged a mass wedding in which his officers married Persian noblewomen, and he took two more Persian wives himself. He recruited tens of thousands of Persian youths, trained in Macedonian warfare, into his army. He required his officers, and sometimes his soldiers, to perform proskynesis, the Persian court gesture of obeisance that Greeks read as worship. The policy, known as the fusion of the peoples, aimed to weld Macedonians, Greeks, and Persians into one ruling class. It was never popular with his Macedonian old guard, and after his death much of it was abandoned. But the idea outlived him: the world he made was a mixed world, and it never went back to being separate.
His other instrument of fusion was the city. Alexandria in Egypt became the most famous, but he founded or refounded dozens of Alexandrias from Egypt to Central Asia. They were garrisons, markets, and workshops of Greek culture, and they spread a common language, Koine Greek, a simplified form of Greek that became the lingua franca of the eastern Mediterranean and the Near East for centuries. It was in Koine that the Hebrew scriptures were translated, that the New Testament was written, and that traders from the Mediterranean to India could do business. Alexander did not plan all of that. He built the roads and the cities; other people walked them.
Whether Alexander believed himself a god is one of history’s oldest arguments. He demanded honours that Greeks reserved for gods, he traced his ancestry to Heracles and Achilles, and the oracle at Siwa encouraged the idea that his true father was divine. Practical men in his court treated the claim as politics: a ruler who was more than a king could hold together an empire of many peoples. Sincere or staged, the claim shaped the Hellenistic age that followed, in which kings routinely presented themselves as gods on earth.
Alexander left no clear heir. His half-brother was intellectually disabled, his wife Roxana was pregnant, and his generals, the Diadochi, the Successors, each held an army. Within a generation the empire he had built was carved into rival kingdoms by decades of war. Ptolemy took Egypt and founded a dynasty that would last until Cleopatra VII, the last ruler of Hellenistic Egypt, died in 30 BCE. Seleucus took the eastern lands, from Mesopotamia to the borders of India. Antigonus and his descendants held Macedon and Greece. The single empire was gone, but the Greek-speaking kingdoms that replaced it kept Alexander’s world intact for three centuries.
His body became a prize. Ptolemy intercepted the funeral cortege carrying Alexander’s remains and brought them to Egypt, first to Memphis and then to Alexandria, where the tomb became a place of pilgrimage. Centuries later, Julius Caesar and Augustus are said to have visited it. The tomb’s location was eventually lost, and it remains one of archaeology’s most sought-after finds. The conqueror who had given the world a new map could not keep his own grave.
The age Alexander opened is called the Hellenistic age, and its achievements were enormous. Alexandria in Egypt became the greatest centre of learning of the ancient world, home to a library and a museum where scholars mapped the earth, measured its circumference, dissected the human body, and wrote the mathematics that would be studied for two thousand years. Greek art, theatre, and philosophy travelled east to India, where they met Buddhism and left their mark on its sculpture, and west to Rome, where they became the foundation of Roman culture. The Mediterranean world and the Near East became one connected space, and they stayed connected.
His legend travelled further than his armies. In Persian tradition he became Iskandar, a figure of wisdom and exploration. In Arabic and later Islamic literature he appeared as Dhul-Qarnayn, the Two-Horned One, a world-traveller and builder of barriers against chaos. Medieval Europe turned him into a chivalric hero, the subject of romances in a dozen languages, a king who flew in a cage lifted by griffins and descended to the bottom of the sea in a glass barrel. The historical Alexander and the legendary Alexander are different men, but the legend is itself evidence: few lives have given so many cultures so much to retell.
Modern historians are more divided. Some see a visionary who imagined a united world. Others see a conqueror whose campaigns killed hundreds of thousands, destroyed cities, and ended in an empire that collapsed the moment he died. Both readings are true, and the tension between them is why he is still argued about. Alexander conquered the known world before he was thirty, and then he died, leaving no plan for what came next. The world he made, mixed, connected, and Greek-speaking, outlasted the empire he built. That is his real monument: not the territory he held, but the civilisation that grew out of it.
This entry draws on the ancient accounts of Alexander’s life and campaigns, including Arrian’s Anabasis of Alexander, Plutarch’s Life of Alexander, and the histories of Diodorus Siculus and Quintus Curtius Rufus, together with the Encyclopaedia Britannica and the standard modern histories of the Hellenistic world. Where the ancient sources disagree, notably on the cause of Alexander’s death and the burning of Persepolis, the disagreement is noted in the text.