Conquest of the Persian Empire

Asia Minor

Alexander’s army crossed the Hellespont in 334 BC with approximately 48,100 soldiers, 6,100 cavalry and a fleet of 120 ships with crews numbering 38,000, drawn from Macedon and various Greek city-states, mercenaries, and feudally raised soldiers from Thrace, Paionia, and Illyria. (However, Arrian, who used Ptolemy as a source, said that Alexander crossed with more than 5,000 horse and 30,000 foot; Diodorus quoted the same totals, but listed 5,100 horse and 32,000 foot. Diodorus also referred to an advance force already present in Asia, which Polyaenus, in his Stratagems of War (5.44.4), said numbered 10,000 men.) He showed his intent to conquer the entirety of the Persian Empire by throwing a spear into Asian soil and saying he accepted Asia as a gift from the gods. This also showed Alexander’s eagerness to fight, in contrast to his father’s preference for diplomacy.

After an initial victory against Persian forces at the Battle of the Granicus, Alexander accepted the surrender of the Persian provincial capital and treasury of Sardis; he then proceeded along the Ionian coast. Though Alexander believed in his divine right to expend the lives of men in battle, he did experience sorrow, as those who died were rewarded generously: “To the relatives of his fallen, Alexander granted immunity from taxation and public service”. Whether it was his own warriors or the Persian forces opposing him, Alexander chose to respect those who died. He even went so far to set up statues to honor and respect these people. Though this did not directly influence the culture of the Persians they did not feel the need to begin a rebellion as their men and rulers were treated with proper respect. At Halicarnassus, in Caria, Alexander successfully waged the first of many sieges, eventually forcing his opponents, the mercenary captain Memnon of Rhodes and the Persian satrap of Caria, Orontobates, to withdraw by sea. Alexander left the government of Caria to Ada, who adopted Alexander.

From Halicarnassus, Alexander proceeded into mountainous Lycia and the Pamphylian plain, asserting control over all coastal cities to deny the Persians naval bases. From Pamphylia onwards the coast held no major ports and Alexander moved inland. At Termessos, Alexander humbled but did not storm the Pisidian city. At the ancient Phrygian capital of Gordium, Alexander “undid” the hitherto unsolvable Gordian Knot, a feat said to await the future “king of Asia”. According to the story, Alexander proclaimed that it did not matter how the knot was undone and hacked it apart with his sword.

The Levant and Syria

Alexander journeyed south but was met by Darius’ significantly larger army which he easily defeated, causing Darius to panic. Although he was chased by some troops, “Alexander treated them (his family) with the respect out of consideration”, which demonstrated his continued generosity and kindness towards those he conquered. Darius fled the battle, causing his army to collapse, and left behind his wife, his two daughters, his mother Sisygambis, and a fabulous treasure. He offered a peace treaty that included the lands he had already lost, and a ransom of 10,000 talents for his family. Alexander replied that since he was now king of Asia, it was he alone who decided territorial divisions.

Alexander the Great, although a generous man in victory, eventually recognized the power that he was capable of when he would defeat an enemy in war. Following the siege of Tyre in 332, the enemy he defeated, Darius, attempted to present terms of unconditional surrender but Alexander became ruthless. He realized that he had control and could receive much more. Darius was thus forced to come back. “This time the offer was impressive. Darius offered all territory as far as the Euphrates… a colossal ransom of 30,000 talents for his family…invited to marry his eldest daughter”. This new change in diplomatic relations induced panic among the leaders of the surrounding nations, as they feared a similar defeat. This led some barbarian cultures simply choosing to abdicate power to Alexander in order to avoid certain death.

Alexander proceeded to take possession of Syria, and most of the coast of the Levant. In the following year, 332 BC, he was forced to attack Tyre, which he captured after a long and difficult siege. Alexander massacred the men of military age and sold the women and children into slavery.


When Alexander destroyed Tyre, most of the towns on the route to Egypt quickly capitulated, with the exception of Gaza. The stronghold at Gaza was heavily fortified and built on a hill, requiring a siege. Alexander came upon the city only to be met with a surprising resistance and fortification. When “his engineers pointed out to him that because of the height of the mound it would be impossible… this encouraged Alexander all the more to make the attempt”. The divine right that Alexander believed he had gave him confidence of a miracle occurring. After three unsuccessful assaults, the stronghold fell, but not before Alexander had received a serious shoulder wound. As in Tyre, men of military age were put to the sword and the women and children were sold into slavery.

Jerusalem opened its gates in surrender, and according to Josephus, Alexander was shown the Book of Daniel’s prophecy, presumably chapter 8, which described a mighty Greek king who would conquer the Persian Empire. He spared Jerusalem and pushed south into Egypt.

Alexander advanced on Egypt in later 332 BC, where he was regarded as a liberator. He was pronounced the new “master of the Universe” and son of the deity of Amun at the Oracle of Siwa Oasis in the Libyan desert. Henceforth, Alexander often referred to Zeus-Ammon as his true father, and subsequent currency depicted him adorned with rams horn as a symbol of his divinity. During his stay in Egypt, he founded Alexandria-by-Egypt, which would become the prosperous capital of the Ptolemaic Kingdom after his death.

Assyria and Babylonia

Leaving Egypt in 331 BC, Alexander marched eastward into Mesopotamia (now northern Iraq) and again defeated Darius, at the Battle of Gaugamela. Darius once more fled the field, and Alexander chased him as far as Arbela. Gaugamela would be the final and decisive encounter between the two. Darius fled over the mountains to Ecbatana (modern Hamedan), while Alexander captured Babylon.


From Babylon, Alexander went to Susa, one of the Achaemenid capitals, and captured its legendary treasury. He sent the bulk of his army to the Persian ceremonial capital of Persepolis via the Royal Road. Alexander himself took selected troops on the direct route to the city. He had to storm the pass of the Persian Gates (in the modern Zagros Mountains) which had been blocked by a Persian army under Ariobarzanes and then hurried to Persepolis before its garrison could loot the treasury.

On entering Persepolis, Alexander allowed his troops to loot the city for several days. Alexander stayed in Persepolis for five months. During his stay a fire broke out in the eastern palace of Xerxes and spread to the rest of the city. Possible causes include a drunken accident or deliberate revenge for the burning of the Acropolis of Athens during the Second Persian War.

Fall of the Empire and the East

Alexander then chased Darius, first into Media, and then Parthia. The Persian king no longer controlled his own destiny, and was taken prisoner by Bessus, his Bactrian satrap and kinsman. As Alexander approached, Bessus had his men fatally stab the Great King and then declared himself Darius’ successor as Artaxerxes V, before retreating into Central Asia to launch a guerrilla campaign against Alexander. Alexander buried Darius’ remains next to his Achaemenid predecessors in a regal funeral. He claimed that, while dying, Darius had named him as his successor to the Achaemenid throne. The Achaemenid Empire is normally considered to have fallen with Darius.

Alexander viewed Bessus as a usurper and set out to defeat him. This campaign, initially against Bessus, turned into a grand tour of central Asia. Alexander founded a series of new cities, all called Alexandria, including modern Kandahar in Afghanistan, and Alexandria Eschate (“The Furthest”) in modern Tajikistan. The campaign took Alexander through Media, Parthia, Aria (West Afghanistan), Drangiana, Arachosia (South and Central Afghanistan), Bactria (North and Central Afghanistan), and Scythia.

Spitamenes, who held an undefined position in the satrapy of Sogdiana, in 329 BC betrayed Bessus to Ptolemy, one of Alexander’s trusted companions, and Bessus was executed. However, when, at some point later, Alexander was on the Jaxartes dealing with an incursion by a horse nomad army, Spitamenes raised Sogdiana in revolt. Alexander personally defeated the Scythians at the Battle of Jaxartes and immediately launched a campaign against Spitamenes, defeating him in the Battle of Gabai. After the defeat, Spitamenes was killed by his own men, who then sued for peace.

Problems and plots

During this time, Alexander took the Persian title “King of Kings” (Shahanshah) and adopted some elements of Persian dress and customs at his court, notably the custom of proskynesis, either a symbolic kissing of the hand, or prostration on the ground, that Persians showed to their social superiors. The Greeks regarded the gesture as the province of deities and believed that Alexander meant to deify himself by requiring it. This cost him the sympathies of many of his countrymen, and he eventually abandoned it.

A plot against his life was revealed, and one of his officers, Philotas, was executed for failing to alert Alexander. The death of the son necessitated the death of the father, and thus Parmenion, who had been charged with guarding the treasury at Ecbatana, was assassinated at Alexander’s command, to prevent attempts at vengeance. Most infamously, Alexander personally killed the man who had saved his life at Granicus, Cleitus the Black, during a violent drunken altercation at Maracanda (modern day Samarkand in Uzbekistan), in which Cleitus accused Alexander of several judgemental mistakes and most especially, of having forgotten the Macedonian ways in favour of a corrupt oriental lifestyle.

Later, in the Central Asian campaign, a second plot against his life was revealed, this one instigated by his own royal pages. His official historian, Callisthenes of Olynthus, was implicated in the plot; however, historians have yet to reach a consensus regarding this involvement. Callisthenes had fallen out of favor by leading the opposition to the attempt to introduce proskynesis.

Macedonia in Alexander’s absence

When Alexander set out for Asia, he left his general Antipater, an experienced military and political leader and part of Philip II’s “Old Guard”, in charge of Macedon. Alexander’s sacking of Thebes ensured that Greece remained quiet during his absence. The one exception was a call to arms by Spartan king Agis III in 331 BC, whom Antipater defeated and killed in battle at Megalopolis the following year. Antipater referred the Spartans’ punishment to the League of Corinth, which then deferred to Alexander, who chose to pardon them. There was also considerable friction between Antipater and Olympias, and each complained to Alexander about the other.

In general, Greece enjoyed a period of peace and prosperity during Alexander’s campaign in Asia. Alexander sent back vast sums from his conquest, which stimulated the economy and increased trade across his empire. However, Alexander’s constant demands for troops and the migration of Macedonians throughout his empire depleted Macedon’s manpower, greatly weakening it in the years after Alexander, and ultimately led to its subjugation by Rome.

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