For Arrian, Curtius, and Diodorus, and Plutarch, as well as Homer, Euripides, and Herodotus, the Loeb Classical Library editions (Cambridge, Mass.: Harvard University Press) offer readable English translations alongside the original language of the ancient sources. For Justin, see J. C. Yardley's translations: Justin. Epitome of the Philippic History of Pompeius Trogus (Atlanta: Scholars Press, 1994), and Justin. Epitome of the Philippic History of Pompeius Trogus. Volume I. Books 11–12: Alexander the Great. Commentary by Waldemar Heckel (Oxford: Oxford University Press, 1997). Charles A. Robinson, The History of Alexander the Great. Vol. 1 (Providence: Brown University, 1953) translates the “fragments” of the “lost” historians of Alexander, meaning quotations and paraphrases of earlier ancient sources found in later, surviving sources.

Modern studies of Alexander are overwhelmingly numerous and diverse. Waldemar Heckel and Lawrence A. Tritle, editors, Alexander the Great: A New History (Chichester, U.K. and Malden, Mass.: Wiley-Blackwell, 2009), pp. 311–348 provide an extensive bibliography. Waldemar Heckel, Who's Who in the Age of Alexander the Great: Prosopography of Alexander's Empire (Malden, Mass. and Oxford: Blackwell, 2006) gives short descriptions, including source citations, for many individuals known from the history of Alexander. The spectrum of modern interpretations of Alexander's personality and aims ranges from the visionary leader promoting the “brotherhood of man” imagined by William Woodthorpe Tarn in Alexander the Great (Cambridge: Cambridge University Press, 1948) to the near sociopath seemingly unable to sate his blood lust conceived by Ernst Badian in “Alexander the Great and the Loneliness of Power,” in Studies in Greek and Roman History (Oxford: Oxford University Press, 1964), pp. 192–205, and by A. B. Bosworth in Conquest and Empire: The Reign of Alexander the Great (Cambridge: Cambridge University Press, 1988) and Alexander and the East: The Tragedy of Triumph New ed. (Oxford: Oxford University Press, 2004).

A truce resolving the potential war between father and son came unexpectedly through the intervention of Demaratus, a Greek from Corinth who enjoyed a relationship of “guest-friendship” with the Macedonian royal family. That status allowed Demaratus to speak frankly to the king. Since much of the venom in the quarrel between Alexander and his father centered on their relative status in the eyes of the Macedonian elite, it took an outsider to make the peace. Demeratus reproached Philip for the disunity he had created in his own house at this critical time, when he was trying to maintain an alliance among Greeks for a high-risk invasion of Persia. Philip followed the advice and reached out to his son.

No source records the message that Philip sent to Alexander. Whatever words Philip used with his son, they tipped the balance of a difficult dilemma for Alexander: were his chances of survival, success, and honor better if he rebelled against his father with the Illyrians as allies, or if he returned to Pella and to the life-and-death competition for preeminence in the violent arena of the Macedonian court? Alexander returned home in late 337. It cannot have been a light-hearted reunion, and there is no sign that Alexander and his father ever again enjoyed a relationship of mutual esteem and confident, shared purpose.

In the autumn of 332, the Macedonian army marched southward along the coast from Tyre. All of the cities on his route surrendered without a fight, except one. Battis, the eunuch whom the Persian king had put in charge of Gaza, refused to allow Alexander to enter his city; he had stored food and hired Arabian mercenaries to withstand a siege. Alexander could easily have bypassed Gaza. The city, on a shoal off shore, posed no impediment to his progress or any serious threat from behind once he had passed. But Alexander was fiercely determined in his treatment of enemies. Those who cooperated he accepted as supporters. Those who resisted he destroyed. His view of natural justice, of the proper ordering of the world of human affairs (with himself at its pinnacle), demanded nothing less. When Parmenion told him that Gaza's lofty fortifications rendered it nearly impregnable, Alexander replied that the challenge alone required him to capture it. When Battis sent a secret assassin masquerading as a suppliant, who nearly succeeded in murdering Alexander, the city's fate was sealed. Alexander ordered his engineers to construct siege machines and personally took the leading role in their deployment. He stood so close to the enemy's walls that a catapult on the ramparts shot him with a missile that penetrated his metal armor and lodged in his shoulder. The wound bled profusely, and his friend Philip narrowly saved his life by pulling out the massive arrow. Even as he recovered from this wound, he stood at the front lines and was hit by a stone flung by an enemy's sling.

The city's defiance justified, for Alexander, a merciless punishment when finally he breached its walls. Every male defender of Gaza was killed, and every woman and child was sold as a slave. When Battis was brought before him, Alexander announced that he would be punished with torture. Had Battis pled for mercy, such an admission of inferiority might have appeased the king's sense of honor. But Battis held his tongue, and Alexander's rage increased. His men pierced Battis's ankles with cords and dragged him, still living, behind a chariot. This gruesome spectacle reenacted the scene in Homer's Iliad when Achilles drags the body of the fallen Trojan hero Hector around the walls of Troy. As much as any incident in Alexander's career, the siege of Gaza and the punishment of Battis reveal essential facts of the king's character. When his superiority was denied, his rage was implacable. And in his rage, he expressed himself through the dramatic vocabulary of the heroic Greek literature on which he was raised.

Alexander had treated the warhorse Bucephalas as he wanted to be treated himself – by persuasion rather than compulsion. According to Plutarch, Philip knew his son could not be forced to do anything, only persuaded through reasoning. Recognizing this trait, in addition to Alexander's boundless desire for knowledge, Philip secured the most persuasive teacher he could find to educate his son to become the best possible successor to the throne of a world power: the scientist, philosopher, and political theorist Aristotle. Aristotle was the same age as Philip, born in the late 380s, and although Greek he had spent his childhood in the Macedonian court, where his father was employed as the official physician. He and Philip were most likely childhood friends. When Aristotle was about eighteen years old, he left Macedonia to study at Athens with Plato, the leading philosopher of the time and himself a student of the famously controversial Socrates. Plato's curriculum emphasized mathematics, geometry, political theory, and ethics. Aristotle became the best-educated person in Greece and, in later times, the most influential thinker from ancient Greece. During his long career, he lectured on a dazzling diversity of subjects: botany, zoology, geography, mathematics, geometry, rhetoric, political history, political philosophy, strategic policy, literary theory, metaphysics, astronomy, the meaning of dreams, and philosophy as a practical guide for living a life of excellence (aretē).

Philip sent Alexander and his Companions to study under this foreign teacher in a sacred location, the Sanctuary of the Nymphs in Mieza, two days’ journey from the capital. The teenagers lived and studied apart from their parents and the rest of Macedonian life. Philip spared no expense in setting up this private school for his son and a select few young members of the Macedonian social elite. Philip believed that this special and high-powered education away from court, with a great teacher who uniquely combined theoretical knowledge with its practical application, would produce the best possible king and the best possible friends and advisors for him.

Alexander had dreamed of surpassing Dionysus and Heracles by continuing into the unexplored (by Greeks) east until he had encircled the world. Now he had turned away from the dream. The pain of this failure was vivid. Still, he marched south along the Indus River, reaching one extreme limit of the terrestrial world at Pattala at the upper end of the Indus Delta. Pattala's inhabitants had fled, but Alexander persuaded them to return to their town and help him defend it against neighboring tribes. He ordered construction of a harbor and a fortified citadel and wells and irrigation in the countryside to support more productive farming. Alexander was governing the strip of India that he covered, following his vision of empire. He relied more than ever on local leaders, while also still placing Macedonians in positions of command. His most important Indian ally was Porus, and Alexander worked to strengthen this former opponent's rule, to extend his territory, and to ensure his ability to govern as a loyal and powerful ally.

While navigating his way through the confusing tangle of waterways of the delta running to the Indian Ocean, Alexander lost several ships in the treacherous currents and tides. At the edge of the sub-continent, he performed the sacrifices that Ammon in Egypt had prescribed to mark his success on reaching Ocean. He then sailed out to sea and sacrificed to Poseidon, the god of the seas, just as he had done ten years earlier when crossing the Hellespont into Asia. He poured an offering of wine into the water and threw in the golden cup after it, praying that the god grant his fleet a safe return to Mesopotamia. He returned to the delta and ordered a second harbor constructed, the infrastructure for sustained commerce by sea between India and his empire to the west. He wanted travelers and merchants to have an alternative to the laborious and expensive overland trip.

Ancient writers agree that Alexander was extraordinary, more like a god than a human in everyone’s eyes – especially his own. In writing this brief biography for non-specialists, we accept the word of those writers based on what seems plausible to our (necessarily limited) understanding of Alexander’s time and place. Our book, therefore, stands on the assumption that the opinions of the ancients must be given great weight, or the story of Alexander’s life will make no sense at all. We are therefore diverging from the approach of some prominent modern scholarship on Alexander, especially the opinion that rejects the value of writing the life of such an enigmatic man. We are writing the story of an ancient life.

Guided by that goal, we pay special attention to the ancient Greek literature that Alexander treasured as sources of inspiration and reflection. His knowledge of these texts reached a depth that is difficult for a modern age to appreciate: to the endof his life, whether sober or drunk, he could recognize, quote, and even enact passages from the authors that meant so much to him, especially Homer and Euripides. The surviving remnants of this literature offer clues to the meaning of Alexander’s words and deeds, and we have tried to include this evidence often (and there would be still more citations in a longer book!). By emphasizing Alexander’s reliance on these texts in understanding his world, his status, and his action, we hope to contribute to a return to a tradition of interpreting Alexander that offers a more source-based view than the modern tendency in some scholarship to see Alexander as little more than a pathological mass murderer.

By early 330 Alexander had sent the Great King of Persia fleeing to the northern corner of his empire. Alexander was master of Egypt and held the Persian capital Persepolis. The treasuries of the empire were his, and his innovative policies of economic reform, (limited) cultural integration, and political stability were going into effect over millions of square miles. The Greeks were avenged many times over for whatever injuries the Persians had inflicted in previous centuries. Alexander's body bore many scars from battlefield surgery to treat missile wounds, and his men were veterans of an unbroken string of victories against fortified cities and armies that invariably outnumbered them. Alexander could have declared victory and settled down to rest and govern amid wealth and comfort, enjoying a well-earned and universally acknowledged reputation as the greatest victor the world had ever seen, a status that his world respected and lauded (as has, for that matter, every other age in human history).

No one met Alexander's ideal; none of his companions, events showed, measured up to the standard of being kratistos. When Alexander died, he left detailed plans for grand schemes that would unify his empire and expand it, a mixed realm ruled by Macedonians, Greeks, and capable men of any nation loyal to his vision. The plans included a thousand warships, larger than any ever seen, for a naval expedition to North Africa, Sicily, and Spain; they described a road, equipped with ports and shipyards, stretching from Egypt to the Pillars of Heracles, where the Mediterranean met the Atlantic; six great temples would be erected in Greece and Macedonia; finally – the culmination of a vision of a mixed culture redefining power in the world – his plans called for new cities as homes for populations transferred from Asia to Europe and from Europe to Asia. As Diodorus reports, Alexander intended through intermarriages and homesteads, “to put the greatest continents into a partnership of harmony and love based on family ties.” Perdiccas presented all of these plans to the assembled army. The soldiers agreed with his judgment that they were too difficult and too expensive. Not a single one was carried out. The generals all proclaimed their support for Alexander's family, pledging to support his impaired brother, who would share the kingship with the child soon to be born to Alexander's pregnant wife, if the baby was male. Behind these empty words they were all frantically crafting their own schemes and promoting their own narrow interests.

Alexander commanded a large army by Macedonian and Greek standards. As he started his expedition in 334 he had 10,000 men in his advance force already in Asia, 32,000 infantry (heavily armed phalanx-men and lightly armed, maneuverable skirmishers), and 5,000 cavalry. “The Greeks” provided significant contingents of men, and Alexander's expeditionary force probably comprised about 40 percent Macedonians, 40 percent Greeks, and 20 percent other Balkan peoples. To keep his homeland secure, Alexander left a garrison of 12,000 infantry and 1,500 cavalry under Antipater, an experienced commander of Philip's generation. Antipater was reliable. During the traditional wine-soaked dinner parties that were the mainstay of social life in Macedonia, Philip used to say, “Oh, now we really have to drink; Antipater is here to stay sober.”

But compared to his enemy's forces, Alexander's army was puny. Over the 200 years of its history the Persian Empire had grown vast. Its heartland, the home of the ethnic Persians, was Iran, but its provinces extended to what is now Turkey in the west, to Afghanistan and the Indus River Valley in India and Pakistan in the east, to the steppes of the Central Asian republics in the north, and to Egypt in the south. At least thirty different peoples were subjects of Persia, administered locally by regional governors called “satraps.” The imperial territory of Persia was fifty times larger than mainland Greece and Macedonia combined; its population was twenty-five times more numerous. The Great King held supreme power, ruling from great palaces in several capital cities. His subjects’ duties were to pay taxes, send soldiers to his army, and remain loyal. The Macedonians were beggars compared to the Persian king. His treasuries contained mounds of gold and silver, ready to be struck into coins at royal command. His army boasted 100,000 infantry from the many peoples of the empire, but his pride was the cavalry, 20,000 strong at full muster. The Persian navy was lavishly funded and large, with the best ships and sailors furnished by the Phoenicians, a people with centuries of experience on the sea. The Great King also employed tens of thousands of Greek mercenaries as heavy infantry – the superiority of Greeks at fighting on foot was universally recognized. An army must be able to move, and toward this end, the Persian Empire was crisscrossed with an elaborate system of roads linking the major centers. Nevertheless, the distances were vast and the terrain often rough. The empire's extent, the large ethnic diversity of the huge army, and the babble of different languages of its troops created perpetual challenges of logistics and command.

The satrapy of Bactria (Afghanistan) occupied the northeastern corner of the Persian Empire, as distant from Persepolis as Persepolis was from Macedonia. The Bactrian peoples were toughened by their environment, which was blazing hot on its upland plains, freezing cold in its mountain heights, and largely dry as a bone, except for occasional rivers that gouged channels through rock and sand. In this land, conquest would be hard, and rule would be harder.

To bring Bactria into his empire, Alexander made a remarkable decision in late 329, upon reaching the city of Bactra (today Balkh), the capital of the satrapy and according to legend the most ancient city in the world. Bactra was famous as sacred to the religion of the Persian kings, which is today called Zoroastrianism after its founding prophet, Zoroaster. Zoroastrian believers worshipped Ahura Mazda as the supreme deity of the universe. He was the source of all good, and his worshippers prayed constantly for his victory, for this god was in perpetual battle against evil. Fire was sacred in the Zoroastrian faith, and its priests nurtured flames kept burning and pure in the temples. To pollute a fire was sacrilege, and there was nothing more polluted than a corpse. Accordingly, the people of Bactria did not burn their dead, as the Macedonians and Greeks often did, according to their own notions of respect for the deceased. Instead, the inhabitants of Bactra kept dogs whose role was to eat the dying and the dead, whose bodies were left lying in the streets of the city. They called these animals “Undertakers.”