A throne and an army at twenty
Alexander III became king of Macedon in 336 BC at twenty, after his father Philip II was assassinated at a wedding by one of his own bodyguards. He spent his first year putting down revolts in the Balkans and destroying the city of Thebes when it rebelled, then crossed into Asia Minor in 334 BC to make war on the Achaemenid Persian Empire. Victories at the Granicus, Issus and Gaugamela broke Persian resistance within the Great King Darius III’s own lifetime; Alexander went on to occupy Egypt, where he was crowned pharaoh and founded Alexandria, before pushing east through Mesopotamia, Persia and Central Asia into northwestern India. His army’s refusal to go further forced a return march, and Alexander died in Babylon in June 323 BC, aged thirty-two, having built one of the largest empires assembled up to that point.
A decade of campaigns
No account written during Alexander’s own lifetime survives complete. The two fullest ancient biographies, by Arrian and Plutarch, were composed roughly four and a half and four hundred years respectively after his death — Arrian working mainly from now-lost campaign histories by men who had served with Alexander, Plutarch drawing on a wider and less disciplined range of anecdote for his life-and-character portraits. Diodorus Siculus, writing in the first century BC, supplies additional detail on the political manoeuvring around Philip’s murder. Because none of these authors were eyewitnesses, historians treat vivid personal scenes — dreams before his birth, the taming of Bucephalas, an encounter with the philosopher Diogenes — as material shaped for effect long after the events they describe, even where the broad military chronology built from multiple sources is considered reasonably secure.
Plutarch’s Alexander, centuries later
Alexander inherited from Philip an army already reorganised around the Macedonian phalanx and heavy companion cavalry, together with a treasury and siege expertise built for exactly this kind of campaign. Persian forces were large but drew on satrapies of uneven loyalty, and Darius III’s personal flight from two major battlefields, at Issus and Gaugamela, cost his side both momentum and the appearance of invincibility. Alexander also moved fast and improvised tactically, adapting siege technique at Tyre and cavalry deployment in India to local conditions rather than repeating a single formula. Just as important, he took care to be crowned or accepted in local terms wherever he went, as pharaoh in Egypt among other examples, which reduced the need to hold every conquered region purely by force.
A birth story built for a king
Historians disagree about how much of Alexander’s supposed divine ancestry originated with Alexander himself, promoted to justify a claim to more than ordinary kingship, and how much was added afterward by biographers keen to explain his achievements. His exact cause of death at Babylon was not recorded and remains unknown, feeding centuries of speculation without resolution. Even his birth date is uncertain by a day. More broadly, scholars differ over how far to trust the character drawn by Plutarch, ambitious, curious, prone to rage, against the more sober military narrative in Arrian, since the two writers had different sources, different aims, and were working centuries apart from each other as well as from their subject.
An empire that outlived him only in pieces
Alexander’s death left no settled succession, and his generals fought each other for decades in what became known as the Wars of the Successors, eventually dividing his conquests into rival kingdoms centred on Macedon, Egypt and the former Persian heartland. That fragmentation opened what is now called the Hellenistic period, during which Greek language and culture spread through the eastern Mediterranean and the Near East and mixed with local traditions, producing new forms in religion, philosophy and art. Alexandria in Egypt became one of the ancient world’s great centres of learning. Later commanders, from Roman generals to Napoleon, measured their own campaigns against his, and a body of legend, the Alexander Romance, circulated across languages and centuries, making him a figure of story as much as of documented history.
Worth the length of the shadow he casts
Alexander’s campaigns are worth following for their scale and speed alone — a decade that reshaped the map from the Adriatic to the Indus is not ordinary military history. The harder and more interesting question is how much of the man behind the campaigns is recoverable at all, given that his fullest biographers wrote centuries later from sources that had every reason to flatter or dramatise him. Readers happy to treat him as a legend will find the legend a good one; readers wanting a documented person will find the documentation thinner than the fame suggests, and will need to read the ancient sources against each other rather than trust any single portrait.
