What is granicus, 334 BC?

The first battle was fought at the River Granicus in north-western Asia Minor, against the assembled western satraps rather than Darius himself. The Persian commander Memnon of Rhodes had reportedly urged a scorched-earth strategy, but the satraps chose to fight, lining their cavalry along the far bank. Alexander led the Companion cavalry across in a frontal assault, won a hard cavalry melee in which he was nearly killed, and then destroyed the Greek mercenaries in Persian pay.

What is issus, 333 BC?

In November 333 BC Darius III himself marched to confront Alexander and slipped behind him, forcing battle on the narrow coastal plain at Issus in the north-eastern corner of the Mediterranean. The confined ground cancelled the Persians' greater numbers (again given in the ancient sources at wildly inflated figures). Alexander's charge with the Companions broke the Persian left and drove towards Darius, who fled the field.

What is gaugamela, 331 BC?

The decisive battle came on 1 October 331 BC on the open plain of Gaugamela near Arbela, ground Darius had chosen and cleared so that his cavalry and scythed chariots could operate. He massed the full imperial levy - the ancient figures (hundreds of thousands, even a million) are not credible and are best treated as illustrative. Alexander advanced obliquely to his right, stretching the Persian line and drawing its cavalry out of position until a gap opened; he then wheeled the Companions in a wedge straight at Darius.

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How did Alexander conquer the Persian empire between 334 and 330 BC, and how far can we reconstruct that conquest from Arrian and the vulgate tradition?

The conquest of the Persian empire: the invasion of Asia in 334 BC (the crossing of the Hellespont and the visit to Troy); the three great set-piece battles of Granicus (334 BC), Issus (333 BC) and Gaugamela (331 BC); the sieges of Tyre and Gaza (332 BC); the seizure of the sinews of empire at Sardis, Babylon, Susa and Persepolis (burned 330 BC); the pursuit and death of Darius III (330 BC); Alexander's generalship; and the nature of the sources, especially Arrian's account drawn from Ptolemy against the vulgate tradition

How Alexander destroyed the Persian empire, 334 to 330 BC - the crossing into Asia and Troy, the battles of Granicus, Issus and Gaugamela, the sieges of Tyre and Gaza, the seizure of Babylon, Susa and Persepolis, and the death of Darius III, weighed through Arrian and the vulgate tradition.

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Between 334 and 330 BC Alexander destroyed the Persian empire. He crossed the Hellespont in 334 BC and made propaganda at Troy, beat the satraps at Granicus (334 BC), defeated Darius III in person and captured his family at Issus (333 BC), took the coast by the sieges of Tyre and Gaza (332 BC), and broke Achaemenid power decisively at Gaugamela (1 October 331 BC). He then seized the sinews of empire - Sardis, Babylon, Susa and Persepolis (burned 330 BC) - and the fugitive Darius was murdered by his own satrap Bessus in 330 BC. The victories rested on combined-arms generalship (phalanx anvil, Companion-cavalry hammer, siegecraft, leadership from the front), but Persian command failures gave them their scale. The sources divide into the reliable Arrian (drawing on Ptolemy and Aristobulus) and the colourful but unreliable vulgate (Cleitarchus, via Diodorus, Curtius and Justin), and modern historians from Tarn to Badian, Bosworth and Hammond disagree on how much credit is Alexander's alone.

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How to read a source on this topic

What this dot point is asking

This dot point asks you to trace how Alexander III of Macedon destroyed the Achaemenid Persian empire in a single campaign between 334 and 330 BC, and to assess how he did it. You need the sequence of events - the crossing of the Hellespont and the visit to Troy in 334 BC, the three set-piece battles of Granicus (334 BC), Issus (333 BC) and Gaugamela (331 BC), the sieges of Tyre and Gaza in 332 BC, the seizure of the "sinews of empire" at Sardis, Babylon, Susa and Persepolis, and the pursuit and death of Darius III in 330 BC. But you also need to explain the generalship behind the victories, and to handle the sources critically, above all the reliable tradition of Arrian (resting on Ptolemy) against the colourful "vulgate." It does not ask for Alexander's background, his campaigns in Egypt or India, or his later kingship; those belong to the other Personalities dot points.

In plain English

Imagine a challenger who takes on the reigning heavyweight champion and beats him not once but three times, each fight bigger than the last, then walks off with the champion's belts, mansion and bank vaults. Alexander did exactly that to Persia. First he punched his way into the ring (crossing into Asia, winning at Granicus), then he floored the champion in person and grabbed his family (Issus), then he knocked him out for good on the champion's home turf (Gaugamela) and emptied his treasuries (Babylon, Susa, Persepolis). The last twist is that the champion was finished off by one of his own cornermen (Bessus). And because the two people telling the story disagree - one a careful reporter using eyewitnesses (Arrian, via Ptolemy), the other a dramatic storyteller who loves a scandalous scene (the vulgate) - part of your job is deciding whose version to trust on the details.

The answer

The invasion of Asia, 334 BC

In spring 334 BC Alexander crossed the Hellespont (the modern Dardanelles) from Europe into Asia Minor with a combined Macedonian and allied Greek army - ancient figures vary, but it was in the order of forty thousand infantry and cavalry, and these totals are ancient-source estimates rather than firm counts. He led the invasion under the banner of the League of Corinth as a panhellenic, Homeric war of revenge on Persia. Turning aside to Ilium (Troy), he sacrificed to Athena, honoured the Homeric dead and reportedly exchanged his armour for a sacred shield, deliberately styling himself a new Achilles. The gesture set the tone of the whole campaign: conquest dressed as heroic, avenging crusade.

The three great battles

Granicus, 334 BC: The first battle was fought at the River Granicus in north-western Asia Minor, against the assembled western satraps rather than Darius himself. The Persian commander Memnon of Rhodes had reportedly urged a scorched-earth strategy, but the satraps chose to fight, lining their cavalry along the far bank. Alexander led the Companion cavalry across in a frontal assault, won a hard cavalry melee in which he was nearly killed, and then destroyed the Greek mercenaries in Persian pay. Granicus opened Asia Minor: Sardis, the Lydian capital, surrendered with its treasury, and Alexander advertised the win by sending captured armour to Athena on the Athenian Acropolis.
Issus, 333 BC: In November 333 BC Darius III himself marched to confront Alexander and slipped behind him, forcing battle on the narrow coastal plain at Issus in the north-eastern corner of the Mediterranean. The confined ground cancelled the Persians' greater numbers (again given in the ancient sources at wildly inflated figures). Alexander's charge with the Companions broke the Persian left and drove towards Darius, who fled the field. The victory delivered the Levant, shattered the King's prestige, and handed Alexander the royal family - Darius' mother Sisygambis, his wife Stateira and his children - whom he pointedly treated with honour. Alexander refused Darius' subsequent offers of ransom, territory and a dynastic marriage.
Gaugamela, 331 BC: The decisive battle came on 1 October 331 BC on the open plain of Gaugamela near Arbela, ground Darius had chosen and cleared so that his cavalry and scythed chariots could operate. He massed the full imperial levy - the ancient figures (hundreds of thousands, even a million) are not credible and are best treated as illustrative. Alexander advanced obliquely to his right, stretching the Persian line and drawing its cavalry out of position until a gap opened; he then wheeled the Companions in a wedge straight at Darius. The King fled a second time, and this time his empire went with him. Gaugamela broke central Achaemenid resistance for good.

The sieges of Tyre and Gaza, 332 BC

After Issus, Alexander turned south down the Levantine coast rather than chasing Darius inland, to deny the Persian fleet its harbours. Most Phoenician cities submitted, but the island fortress of Tyre resisted. In a siege of roughly seven months in 332 BC, Alexander built a great mole (a causeway) out from the mainland to the island, deployed siege towers and, with a scratch fleet from the surrendered Phoenician cities, stormed it. Gaza, further south, held out for about two months before it too was stormed. These sieges show his refusal to leave strongpoints in his rear and secured the coast before he entered Egypt (the subject of the next dot point) and turned inland to Mesopotamia.

The sinews of empire: Sardis, Babylon, Susa, Persepolis

Conquest was not only battles; it was the seizure of the Persian state's resources - its royal centres and treasuries, the "sinews" that funded the empire. Sardis had opened its Lydian treasury after Granicus. After Gaugamela the great administrative capitals fell in succession: Babylon surrendered (its satrap Mazaeus went over to Alexander) and Susa yielded an enormous reserve of bullion (ancient sources put it at tens of thousands of talents - figures that are illustrative of scale rather than audited). Alexander then forced the passes into Persia proper and took Persepolis, the ceremonial heart of the Achaemenid dynasty, with the largest treasure of all. In 330 BC the palace complex of Persepolis was burned. Whether this was a drunken act of revenge urged by the courtesan Thais (the vulgate) or a deliberate, symbolic close to the panhellenic war of vengeance for Xerxes' burning of Athens (implied by Arrian) is disputed; the archaeology confirms a great fire but cannot settle the motive. Either way, the destruction of Persepolis signalled that the Achaemenid empire was finished.

The pursuit and death of Darius III, 330 BC

Darius had fled Gaugamela to Ecbatana in Media, trying to raise a fresh army. As Alexander advanced north to Ecbatana and then pursued him east, Darius' own commanders lost faith. In the summer of 330 BC Bessus, satrap of Bactria, and other conspirators seized Darius and, as Alexander closed in, murdered him, leaving his body on the road. Bessus proclaimed himself King as Artaxerxes V. Alexander, finding the dead King, gave him an honourable royal burial - a calculated act presenting himself, not Bessus, as Darius' legitimate successor and avenger. With Darius dead, the war of conquest against the Achaemenid dynasty was effectively over, though the pursuit of Bessus and the hard fighting in the eastern satrapies (the next dot point) lay ahead.

Alexander's generalship

Behind the sequence lies a consistent military method. Alexander fought with combined arms: the deep phalanx of pikemen (armed with the long sarissa) fixed the enemy line as an anvil, while he personally led the elite Companion cavalry (the hetairoi) as a hammer that struck the decisive blow, supported by hypaspists, Thessalian cavalry, and light troops such as the Agrianians. At Gaugamela this became an art form, with an oblique advance that pulled the enemy out of shape before the wedge charge went in. He led from the front and took great personal risks (he was nearly killed at Granicus), read terrain shrewdly (the narrows at Issus), mastered siege engineering (the Tyre mole), and kept his army supplied deep in hostile territory. He also fought a political war, treating Darius' family with honour and burying the dead King, to present himself as legitimate successor rather than mere invader.

How to read a source on this topic

Section III sources for Alexander typically describe (never reproduce verbatim) a passage of Arrian, a scene from the vulgate (Diodorus, Curtius, Justin or Plutarch), or an inscription or coin. Three habits help.

First, place the source in its tradition. Is it from the "good" tradition (Arrian, resting on the campaign eyewitnesses Ptolemy and Aristobulus) or the "vulgate" (deriving from Cleitarchus, who did not serve on the campaign)? Arrian is usually preferred for military and factual matters; the vulgate is richer in anecdote and criticism but far freer with the truth.

Second, fix purpose and sympathy. Ptolemy became King of Egypt and had reason to magnify Alexander and himself; the vulgate writers wrote to entertain and to moralise, so their most vivid scenes (Thais at Persepolis) may be dramatisation. Even the "reliable" Arrian is broadly favourable.

Third, always move from content to reliability to usefulness to perspective, and reach a judgement, rather than merely retelling what the source says. On this topic that usually means testing a colourful vulgate story against Arrian and, where possible, against the archaeology (as with the burning of Persepolis).

Model exam responses

1. Source-analysis response (using a passage in the manner of Arrian). "A passage in Arrian's manner, citing Ptolemy and Aristobulus for the events at Gaugamela, is valuable because Arrian rested his Anabasis on two men who actually campaigned with Alexander, giving us near-eyewitness testimony for the battle and Alexander's tactics. Its usefulness is limited, however, by the fact that Arrian wrote around 450 years later and that Ptolemy, as a general and later a rival king, had motive to magnify Alexander's role and his own. The passage is therefore most reliable for the military course of the battle, but its favourable colouring should be tested against the vulgate and against the physical evidence."

Marker's note: markers reward dating the source, an explicit value/limitation split (eyewitness base versus Ptolemy's bias and the time gap), and testing rather than simple acceptance.

2. Essay paragraph (generalship versus Persian weakness). "Gaugamela shows that the conquest was won by generalship but completed by Persian failure. Alexander's oblique advance drew the Persian cavalry out of line and opened the gap through which his Companion wedge charged straight at Darius - a manoeuvre Arrian, following Ptolemy, records in detail and which Hammond rates as first-rate command. Yet the rout turned on Darius fleeing while much of his army still stood, and on the later treachery of Bessus, who murdered his own King in 330 BC. As Bosworth argues, Achaemenid command failures converted battlefield defeats into total collapse. The victory was Alexander's design; its completeness was also Persia's undoing."

Marker's note: this paragraph scores because it argues a two-sided case with a dated example, uses a named source (Arrian/Ptolemy) and named historians (Hammond, Bosworth), and answers the question rather than narrating the battle.

Command words and how to use a source

Outline/describe wants a few clearly separated points; explain wants a point, evidence and why it matters; assess/evaluate/to what extent wants a sustained argument reaching a supported judgement.

Using a source properly means four things every time: (1) content, what it actually shows; (2) reliability, who produced it, when and why; (3) usefulness, what question it can help answer and how far; (4) perspective, whose viewpoint it gives and what it omits. For Alexander, always state whether a source belongs to the reliable tradition (Arrian, via Ptolemy and Aristobulus) or the vulgate (Cleitarchus, via Diodorus, Curtius, Justin), because that usually decides its value.

Weaving in historiography means using a historian's named position to build the argument, for example "as Badian argues, the sources' admiration should not be mistaken for objectivity," used to qualify a specific claim rather than dropped in as decoration.

Common exam traps

Narrating the campaign instead of arguing: A "to what extent" question on the conquest wants an argument (generalship versus Persian weakness, for example), not a blow-by-blow of every battle. Select evidence to prove a point.
Quoting ancient troop and casualty numbers as fact: The figures for Darius' armies (hundreds of thousands, even a million at Gaugamela) are ancient-source inflations; flag them as unreliable rather than repeat them as data.
Confusing who Alexander beat: Granicus was against the satraps; Darius was defeated in person at Issus and Gaugamela. Do not put Darius at Granicus.
Treating Arrian as neutral and the vulgate as worthless: Arrian is fullest and most reliable but still favourable; the vulgate is unreliable on fact yet valuable for image and for material Arrian omits. Strong answers weigh the two traditions.

Practice questions

Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.

foundation3 marksOutline the crossing into Asia in 334 BC and the significance of Alexander's visit to Troy.

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A 3-mark "outline" needs the crossing itself, the visit to Troy and why it mattered.

The crossing: In spring 334 BC Alexander led his combined Macedonian and allied army across the Hellespont (the Dardanelles) from Europe into Asia Minor, opening the invasion of the Persian empire (1 mark).
The visit to Troy: He turned aside to Ilium (Troy), where he sacrificed, honoured the Homeric heroes and reportedly took a shield from the temple of Athena, casting himself as a new Achilles (1 mark).
Significance: The gesture was propaganda: it framed the campaign as a panhellenic, Homeric war of Greek against "barbarian" and advertised Alexander as the heir of the heroic past, encouraging his troops and his Greek allies (1 mark).

Marker's note: markers reward the propaganda purpose of the Troy visit, not just the fact that he crossed the Hellespont.

foundation4 marksSource A: a reconstructed dedicatory inscription of this type, in the style of a Greek temple offering, records that Alexander son of Philip and the Greeks (except the Spartans) dedicate these spoils, taken from the barbarians who dwell in Asia. It is an illustrative ExamExplained reconstruction, not a real inscription. Using Source A and your own knowledge, describe what the dedication reveals about how Alexander presented his invasion.

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A 4-mark "describe using the source" needs points drawn from Source A plus supporting knowledge.

A panhellenic war: The dedication names "Alexander and the Greeks" and calls the enemy "the barbarians who dwell in Asia," presenting the invasion not as a private conquest but as a shared Greek crusade of revenge against Persia (1-2 marks).
The pointed exclusion: Naming "the Greeks except the Spartans" advertises that Sparta stood apart from the League of Corinth, so the dedication is also a piece of political propaganda aimed at Greek opinion (1 mark).
Supporting knowledge: This matches Alexander's wider self-presentation after Granicus (334 BC), where he sent captured Persian armour to Athena's temple on the Athenian Acropolis, continuing the Homeric, panhellenic image begun at Troy (1 mark).

Marker's note: markers reward using the actual wording of the source (panhellenic, anti-barbarian, Sparta excluded) rather than a general account of the campaign.

foundation4 marksOutline the events and significance of the Battle of Issus in 333 BC.

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A 4-mark "outline" needs where and when, what happened, the outcome and its significance.

Setting: In November 333 BC Darius III moved behind Alexander and forced a battle on the narrow coastal plain at Issus, in the corner of the north-eastern Mediterranean, where the confined ground cancelled his numerical advantage (1 mark).
The battle: Alexander led the Companion cavalry in a charge against the Persian left and drove towards Darius himself; the Great King fled the field, and his line collapsed (1 mark).
Outcome: This was the first defeat of Darius in person; Alexander captured the Persian camp and the royal family - Darius' mother Sisygambis, his wife and children - whom he treated with conspicuous respect (1 mark).
Significance: Issus shattered Persian prestige, won Alexander the Levant and a propaganda triumph, and let him refuse Darius' subsequent peace offers from a position of strength (1 mark).

Marker's note: markers reward the capture of the royal family and the personal defeat of Darius, not just "Alexander won."

core6 marksExplain how the three battles of Granicus, Issus and Gaugamela progressively destroyed Achaemenid power between 334 and 331 BC.

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A 6-mark "explain" needs each battle as a distinct stage in the collapse of Persian power, causally linked.

Granicus (334 BC): the door into Asia: At the River Granicus in north-western Asia Minor, Alexander defeated the army of the western satraps, opening Asia Minor to conquest and allowing cities such as Sardis to surrender with their resources. It broke Persian regional command but did not touch Darius himself (2 marks).
Issus (333 BC): the King defeated: By defeating Darius in person and capturing the royal family, Issus destroyed the prestige of the Great King, delivered the wealthy Levant, and shifted the psychological balance decisively towards Alexander (2 marks).
Gaugamela (331 BC): the empire broken: On the open plain near Arbela, Darius massed his full imperial levy on ground of his own choosing, yet Alexander's decisive charge routed him a second time. This victory broke central Achaemenid resistance and opened Babylon, Susa and Persepolis, effectively ending the empire as a fighting power (2 marks).

Marker's note: markers reward showing the escalation - a satrapal army, then the King, then the whole empire - not three separate battle narratives.

core6 marksSource B: a reconstructed passage of this type, written in the sober, source-citing manner of Arrian, states that where Ptolemy son of Lagus and Aristobulus agree the author follows them as eyewitnesses who served with the king, and records at Gaugamela only what those companions reported. It is an illustrative ExamExplained reconstruction. Using Source B and your own knowledge, explain why Arrian is a valuable but limited source for the conquest.

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A 6-mark "explain" needs use of the source, Arrian's value and his limitations.

Use of the source: Source B captures Arrian's stated method in the Anabasis of Alexander (early second century AD): he preferred Ptolemy and Aristobulus, and followed them especially where they agreed (2 marks for accurate use).
Value: Ptolemy (later king of Egypt) and Aristobulus were contemporaries who campaigned with Alexander, so Arrian rests on near-eyewitness testimony; his soldierly interest in strategy makes him our fullest and most reliable narrative of the battles and generalship (2 marks).
Limitation: Arrian wrote roughly 450 years after the events and is only as good as his sources: Ptolemy was a general and later a rival king with reason to magnify his own and Alexander's role, and Arrian largely omits the hostile and sensational material the vulgate preserves, so his portrait is favourable and needs testing (2 marks).

Marker's note: markers reward weighing Arrian's eyewitness base against the bias of Ptolemy and the gap of centuries, rather than simply praising Arrian as "reliable."

core6 marksExplain the main features of Alexander's generalship that account for his success in the conquest of Persia.

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A 6-mark "explain" needs several distinct features, each tied to the campaign and to why it worked.

Combined-arms tactics: Alexander fought with the sarissa-armed phalanx as the anvil that pinned the enemy line while he led the Companion cavalry (hetairoi) as the hammer. At Gaugamela (331 BC) his oblique advance to the right drew the Persian cavalry out, opened a gap, and let him charge straight at Darius (2 marks).
Leading from the front and reading terrain: He personally led the decisive charge at Granicus, Issus and Gaugamela, and chose or exploited ground - the narrows at Issus cancelled Persian numbers - accepting great personal risk to seize the moment (2 marks).
Siegecraft and logistics: The seven-month siege of Tyre (332 BC), taken by building a mole out to the island, shows his engineering and refusal to leave a strongpoint in his rear, while his control of supply sustained a long advance deep into Asia (2 marks).

Marker's note: markers reward specific, dated examples of each feature (the hammer-and-anvil, the Issus narrows, the Tyre mole), not a general claim that he was a "military genius."

exam8 marksSource C: a reconstructed passage of this type, in the colourful, dramatic manner of the vulgate tradition, tells how at a drunken victory feast the courtesan Thais urged Alexander to avenge Greece by firing the palace of Xerxes, and how the king, garlanded and torch in hand, led a revelling procession that burned Persepolis to the ground in 330 BC. It is an illustrative ExamExplained reconstruction. Using Source C and your own knowledge, assess the usefulness and reliability of the vulgate tradition as evidence for the conquest.

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An 8-mark "assess usefulness and reliability" answer needs content, usefulness, reliability/limitation and a judgement.

Content: Source C gives the vulgate version of the burning of Persepolis: a spontaneous, drunken act of revenge sparked by Thais at a feast, dramatic and personal in its detail (2 marks).
Usefulness: The vulgate - Diodorus (Book 17), Curtius Rufus, Justin and much of Plutarch, deriving ultimately from Cleitarchus - preserves colour, anecdote and criticism that Arrian omits: the atmosphere of the court, Alexander's excesses and the moral reaction to them. It is valuable for the image and reputation of Alexander and often for material lost elsewhere (2 marks).
Reliability/limitation: The tradition is rhetorical and sensational, shaped to entertain and to moralise; Cleitarchus did not serve on the campaign, so vivid stories like the Thais scene may be dramatisation. Arrian, following the eyewitnesses Ptolemy and Aristobulus, implies instead a deliberate, policy-driven burning, and Persepolis' archaeology confirms only a great fire, not its cause (2 marks).
Judgement: The vulgate is most reliable as evidence for how Alexander was remembered and judged, and only cautiously reliable for events; on a disputed episode like Persepolis it must be tested against Arrian and the material record rather than taken as fact (2 marks).

Marker's note: markers reward separating "what the story reveals about Alexander's reputation" from "whether it literally happened," and testing the vulgate against Arrian and archaeology.

exam25 marksTo what extent was the destruction of the Persian empire between 334 and 330 BC the achievement of Alexander's own generalship rather than the weaknesses of the Achaemenid state? In your response, refer to relevant sources and historians' interpretations.

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A Band-6 response needs a clear thesis, argument lines tied to dated evidence and named historians, a model paragraph and a judgement answering "to what extent."

Thesis: Alexander's generalship was the decisive cause of the conquest - his combined-arms tactics and personal leadership won every field - but it operated on a Persian state whose strategic and command weaknesses gave those victories their scale and speed.
Argument 1: generalship won the battles: Granicus (334 BC), Issus (333 BC) and Gaugamela (331 BC) were all won by the same method: the phalanx pinning the line while Alexander led the Companion cavalry in a decisive charge, twice driving Darius himself from the field. Arrian, drawing on the eyewitness Ptolemy, stresses this tactical mastery, and Hammond reads Alexander as a commander of the first rank.
Argument 2: siegecraft and drive: The seven-month reduction of Tyre and the storming of Gaza (both 332 BC) show he would not leave strongpoints in his rear, while the rapid seizure of Sardis, Babylon, Susa and Persepolis turned battlefield wins into control of the empire's resources. This was method, not luck.
Argument 3: but Achaemenid weakness enabled the scale: Darius twice chose or accepted poor tactical decisions - fighting in the narrows at Issus, then fleeing early at both Issus and Gaugamela, which collapsed armies that were not yet beaten. The empire's reliance on Greek mercenaries and unreliable satraps, and finally Darius' murder by his own officer Bessus in 330 BC, show a state undermined from within.
Argument 4: the sources shape the balance: The favourable Arrian magnifies Alexander's skill; the vulgate (Cleitarchus via Diodorus and Curtius) magnifies fortune and drama. Modern historians divide: Tarn idealised a visionary conqueror, while Badian and Bosworth stress ruthlessness, terror and the fragility of the Persian response, warning against crediting genius alone.
Model paragraph: Gaugamela is the clearest test. Darius chose open ground and massed his full levy, yet Alexander's oblique advance drew the Persian cavalry out, opened a gap, and his charge towards the King decided the day - textbook generalship. But the rout turned on Darius fleeing while much of his army still stood, and on Bessus' later treachery. As Bosworth argues, Achaemenid command failures converted tactical defeats into total collapse; the victory was Alexander's, but its completeness was Persia's undoing as much as his design.
Judgement: To a large extent the conquest was Alexander's achievement, since his generalship won every battle and drove the campaign; but it is not wholly his, because Persian strategic errors, Darius' flights and internal betrayal gave those victories their decisive scale.

Marker's note: markers reward a sustained two-sided argument answering "to what extent," dated battle evidence, and historians (Arrian/Ptolemy, Tarn, Badian, Bosworth, Hammond) used to weigh generalship against Achaemenid weakness.