§-Syllabus dot point

NSWAncient HistorySyllabus dot point

How did Xerxes I use the building program at Persepolis to express Achaemenid kingship and the ideology of a unified empire?

Xerxes and the building program at Persepolis: his completion of the Apadana begun by Darius I, the Gate of All Nations (inscription XPa), the Hundred-Column Throne Hall, the Palace of Xerxes (Hadish) and the Tripylon, the Apadana tribute-bearer reliefs as imperial ideology, his continued building at Susa, and the propaganda function of the royal building inscriptions and reliefs

A focused answer to the HSC Ancient History Personalities dot point on Xerxes' building program at Persepolis: his completion of the Apadana, the Gate of All Nations (XPa), the Hundred-Column Throne Hall, the Palace of Xerxes (Hadish) and the Tripylon, the tribute reliefs as imperial ideology, and his building at Susa.

Generated by Claude Opus 4.813 min answerUpdated 2026-07-01

Reviewed by: AI editorial process; not yet individually human-reviewed

Have a quick question? Jump to the Q&A page

Quick answer

Xerxes I (486 to 465 BC) continued and enlarged the Persepolis program his father Darius I began about 518 BC. He built the Gate of All Nations (inscription XPa) and his own palace, the Hadish; completed the Apadana (around 72 columns) with its tribute reliefs showing some 23 delegations in willing, unviolent procession, and the Tachara; and began the Hundred-Column Throne Hall and the Tripylon, finished by Artaxerxes I. He also continued building at Susa. The trilingual building inscriptions bind construction to Ahuramazda's favour and to the dynasty, so the whole program reads as propaganda for a legitimate, god-sanctioned king ruling a harmonious, unified empire. As Margaret Cool Root argues, this was coordinated royal ideology, though Pierre Briant cautions that the same empire also rested on coercion, and the ceremonial terrace expressed kingship rather than running the government.

Jump to a section

What this dot point is asking
The answer
How to read a source on this topic
Historians on Xerxes' building program

What this dot point is asking

NESA expects you to explain what Xerxes I (reigned 486 to 465 BC) personally contributed to the building program at Persepolis, and what that program reveals about his kingship and imperial ideology. You need the specific buildings and inscriptions, the Gate of All Nations (XPa), the completed Apadana and its tribute-bearer reliefs, the Hundred-Column Throne Hall, the Palace of Xerxes (the Hadish), and the Tripylon, together with his continued work at Susa, and you must be able to argue how the architecture, reliefs, and royal building inscriptions functioned as propaganda projecting a legitimate, god-sanctioned king over a single, harmonious empire.

In plain English

Imagine your father starts building an enormous, jaw-dropping headquarters to show the world how powerful the family firm is, and then dies with it half-finished. You are the heir. You do not knock it down and start your own thing. You finish his grand hall, you add an even bigger private wing for yourself, you build a spectacular front gate that every visitor has to walk through, and you carve your name on it saying "I built this, and so did my father." You do not decorate the walls with pictures of you crushing rivals. Instead you carve a friendly parade of every branch of the firm walking up the stairs with gifts, everyone in their own uniform, nobody forced.

That is exactly what Xerxes did at Persepolis. He completed the giant audience hall (the Apadana) his father Darius began, built the Gate of All Nations, started the Hundred-Column Throne Hall, and put up his own palace, the Hadish, bigger than his father's. The message, repeated in stone and in three languages, was simple: I am the rightful king, the gods chose me, and my many peoples happily stand together under me. The buildings themselves were the advertisement.

The answer

The setting: Persepolis when Xerxes came to the throne

Darius I founded Persepolis (Old Persian Parsa) in Fars, near modern Shiraz, from about 518 BC, on a vast artificial stone terrace roughly 450 by 300 metres cut partly into the mountainside of Kuh-e Rahmat. When Darius died in 486 BC and Xerxes succeeded him, the terrace was a coordinated project only partly built. Persepolis was never a working administrative capital, Susa, Babylon, and Ecbatana carried the day-to-day government, but a ceremonial centre, most famously for the Nowruz (New Year) reception of tribute. Xerxes' central choice was to continue and enlarge his father's vision rather than start afresh: the building program is therefore, before anything else, a statement of dynastic continuity.

The Gate of All Nations (inscription XPa)

The most conspicuously Xerxes structure on the terrace is the Gate of All Nations, the monumental gatehouse he built after 486 BC through which every visitor had to pass before approaching the king. It was a square hall with four columns and doorways on three sides, guarded by colossal stone bulls: human-headed winged bulls in the Assyrian lamassu tradition at the western entrance, and plain, Persian-style bulls at the eastern exit, the same deliberate fusion of borrowed and native forms found across Persepolis. Xerxes' trilingual inscription (XPa, in Old Persian, Elamite, and Akkadian) opens by crediting Ahuramazda, names Xerxes as builder, records his descent from Darius, and states that "much else that is beautiful was built in this Parsa, which I built and which my father built." The gate is thus both a functional entrance and a compact dynastic manifesto.

Completing the Apadana and the tribute-bearer reliefs

The Apadana, the great columned audience hall begun by Darius I, was completed under Xerxes. It comprised around 72 columns in total (36 in the main hall), each roughly 19 metres tall and topped with bull-, lion-, or eagle-headed double protome capitals; only 13 still stand. Its north and east staircases carry the tribute-procession reliefs, whose carving was largely finished in Xerxes' reign: some 23 delegations (the number commonly cited in scholarship), each identified by distinctive dress and regionally specific gifts, animals, textiles, precious vessels, escorted by a Persian or Median usher toward the enthroned king. Crucially, no delegate appears bound, kneeling under a raised weapon, or paraded as a captive, a deliberate departure from the Assyrian palace-relief tradition of chained and beheaded prisoners. This is the ideological heart of the program: an image of an empire of many peoples willingly and peacefully united under the king.

The Hundred-Column Throne Hall, the Hadish, and the Tripylon

Beyond completing his father's work, Xerxes began major buildings of his own. The Throne Hall, also called the Hundred-Column Hall, a vast square hall used for royal audiences and receiving military commanders, was begun by Xerxes and left unfinished at his murder in 465 BC; it was completed by his son Artaxerxes I. The Palace of Xerxes, called in his inscriptions the Hadish (an Old Persian word for palace or dwelling), was his own residence on the highest part of the terrace, noticeably larger than Darius's nearby Tachara, whose completion and inscription Xerxes also oversaw. The small central palace known as the Tripylon (or Council Hall), decorated with reliefs of the king and his nobles, is associated with Xerxes and Artaxerxes I, though its precise attribution is debated. Together these show a king asserting his own monumental presence within, and surpassing, his father's plan.

Building at Susa

Xerxes' program was not confined to Persepolis. At Susa, the empire's chief administrative capital, he continued and added to the palace complex his father Darius had built, and left building inscriptions there (the XS-series texts) in the same trilingual royal formula. This reinforces the point that building was, for Xerxes, a standing royal duty carried out across the empire's centres, not a single vanity project.

The building program as royal propaganda

The unifying thread is propaganda. The architecture fuses borrowed elements, Assyrian gate guardians, Egyptian column details, Ionian and Lydian stonework, into a single new Persian style, so the buildings themselves argue for an empire built by all its peoples. The Apadana reliefs replace conquest imagery with a peaceful, orderly tribute procession, projecting rule by consent. The trilingual inscriptions bind every act of building to Ahuramazda's favour and to the dynasty, presenting Xerxes as the legitimate, god-chosen heir completing a sacred royal project. Because the terrace was ceremonial rather than administrative, its whole purpose was to make Achaemenid kingship visible: a magnificent stage on which the unity of the empire under Xerxes was performed each Nowruz.

Xerxes' building program at a glance

Structure	Xerxes' role	Significance
Gate of All Nations (XPa)	Built new by Xerxes	Ceremonial entrance; dynastic manifesto; Assyrian and Persian fusion
Apadana	Completed (begun by Darius I)	Audience hall; tribute reliefs project willing, unified empire
Hundred-Column Throne Hall	Begun by Xerxes, finished by Artaxerxes I	Vast audience hall; scale of royal power
Palace of Xerxes (Hadish)	Built new by Xerxes	The king's own residence, larger than Darius's Tachara
Tachara (Palace of Darius)	Completed and inscribed by Xerxes	Continuity with and honour to his father
Tripylon	Associated with Xerxes / Artaxerxes I	Central palace with king-and-nobles reliefs
Susa palace	Continued Darius's work	Building as an empire-wide royal duty

How to read a source on this topic

Sources for Xerxes' building program fall into two very different groups, and the first skill is telling them apart. The primary evidence is Achaemenid and archaeological: the buildings and reliefs themselves, and the royal building inscriptions (XPa on the Gate, XPf, the Susa XS-texts). These are contemporary and were commissioned by Xerxes, so they are excellent for what he wanted to project but are, by definition, official self-presentation, not neutral fact. The Greek literary tradition (Herodotus, and later Diodorus Siculus, Quintus Curtius Rufus, Plutarch) is secondary, hostile, and largely silent on Persepolis itself; Herodotus never names the site. Use the Greeks for the Greek and Macedonian reception of Xerxes (including the burning of 330 BC), not for the palace's original meaning.

Three habits. First, read a royal inscription as a claim, not a chronicle: XPa's "which I built and which my father built" is a legitimacy statement, so ask what political work it does. Second, read absence as deliberately as presence: what the Apadana reliefs do NOT show, chains, captives, violence, is central to the argument that this art is ideology. Third, fix attribution and date precisely: distinguish what Xerxes built new (Gate, Hadish), completed (Apadana, Tachara), and merely began (Throne Hall, Tripylon), and treat any illustrative exam reconstruction as a labelled type, never a transcription of a specific real object.

Historians on Xerxes' building program

Margaret Cool Root (The King and Kingship in Achaemenid Art, 1979) is the central modern voice, arguing that Persepolis's art, including the tribute reliefs completed under Xerxes, was a coordinated ideological program constructing an image of a harmonious empire held by consent rather than force. Michael Roaf (Sculptures and Sculptors at Persepolis, 1983) analysed the Apadana reliefs' carving in detail, showing an organised, empire-wide workforce and helping date the program's phases across the reigns of Darius, Xerxes, and Artaxerxes I. Ernst Herzfeld and Erich Schmidt, the Oriental Institute's excavators of Persepolis in the 1930s (Schmidt's Persepolis I-III, 1953 to 1970), established the physical evidence and building sequence on which all later interpretation depends. Pierre Briant (From Cyrus to Alexander: A History of the Persian Empire, 2002) provides the major synthesis and cautions against reading the art purely as benign harmony when the Fortification Archive documents compulsory labour and controlled tribute. Amelie Kuhrt (The Persian Empire: A Corpus of Sources, 2007) assembles and contextualises the royal inscriptions, insisting they be read as official ideology. Together these historians support reading Xerxes' program as deliberate propaganda while resisting the older Greek-derived image of Xerxes as merely a failed and decadent invader.

Model exam responses

1. Source-analysis response (a building inscription of the XPa type). "Source A, an ExamExplained reconstruction of an XPa-type building inscription, is useful evidence for how Xerxes presented his building program, though it must be read as official ideology rather than neutral record. Its content follows the standard Achaemenid formula: it credits Ahuramazda for creation and for making Xerxes king, claims the Gate as the king's own act 'by the favour of Ahuramazda,' and folds his work into his father's ('which I built and which my father built'). This matters because it shows building framed not as decoration but as pious, god-sanctioned royal duty and dynastic continuity. As Amelie Kuhrt stresses, such inscriptions are commissioned self-presentation, so a historian should treat the text as evidence of the image Xerxes wanted, a legitimate heir completing a sacred project, rather than as an impartial account."

Marker's note: markers reward correct decoding of the inscription's formula (divine sanction plus dynastic continuity), an explicit statement that it is official ideology, and a named historian used as argument about function.

2. Essay paragraph (the tribute reliefs as ideology). "The clearest evidence that Xerxes' program was deliberate ideology lies in what the Apadana reliefs, completed in his reign, choose not to show. Across some 23 sculpted delegations no subject is bound, kneeling under a raised weapon, or paraded as a captive, the standard vocabulary of Assyrian palace art a century earlier. Instead a Persian usher rests a hand lightly on each leading delegate's wrist, guiding him forward with his region's gift. As Margaret Cool Root argues, this is a constructed political fiction of willing, universal consent to Achaemenid rule, sculpted on the very staircase every dignitary climbed to reach Xerxes. The reliefs assert not merely that the king was rich, but that his empire was a single, contented order under a legitimate ruler."

Marker's note: this paragraph scores because it uses precise evidence (the 23 delegations, the usher's gesture), explains WHY the detail matters (propaganda, not record), and integrates Root as argument.

3. Short-answer response (the Gate of All Nations). "Xerxes I built the Gate of All Nations after his father Darius I's death in 486 BC, as the monumental entrance through which every visitor to the terrace passed. Its guardian figures show the fusion typical of Persepolis: human-headed winged bulls in the Assyrian lamassu tradition guard the western entrance, plain Persian-style bulls the eastern exit. Xerxes' trilingual inscription (XPa) names him as builder, records his descent from Darius, and claims 'much else that is beautiful' at Persepolis, making the gate a deliberate dynastic statement as much as a functional entrance."

Marker's note: markers reward correct attribution and date, the two bull types, and use of the XPa inscription as evidence of intent.

Command words and technique

Match the verb. "Outline" and "identify and explain" want named, correctly attributed structures (the Gate, the Hadish, the Throne Hall) and their status as built, completed, or begun by Xerxes. "Explain" wants significance or mechanism (why the program signals legitimacy, not just what he built). "Assess"/"evaluate"/"to what extent" demand a sustained JUDGEMENT stated up front and defended, ideally distinguishing ideological from administrative significance. For any source, run four steps: CONTENT (what is depicted or written), ORIGIN (which building or inscription, whose reign, archaeological or literary), USEFULNESS AND RELIABILITY (a royal inscription is contemporary but is official self-presentation; a Greek account is late and hostile; an ExamExplained reconstruction is a labelled type, not a transcription), and SIGNIFICANCE (what it reveals about kingship, legitimacy, or unity). Weave historiography as argument, "Root reads the absence of violence as deliberate ideology, which Briant qualifies by pointing to the coercion the Fortification Archive records," rather than name-dropping at the end.

Common exam traps

Crediting Xerxes with founding Persepolis: Darius I founded it about 518 BC; Xerxes continued and enlarged the program. Be precise about who did what.
Blurring the attributions: Xerxes built the Gate and the Hadish new, completed the Apadana and Tachara, and only began the Throne Hall and Tripylon (finished by Artaxerxes I). Markers reward exactly this precision.
Treating the tribute reliefs as a literal record: The orderly, unviolent procession is a constructed ideology (Root), not a snapshot of how delegations actually behaved.
Confusing Persepolis with an administrative capital: Persepolis was ceremonial; Susa, Babylon, and Ecbatana ran the empire. Its significance is ideological, not governmental.
Relying on the Greeks for the buildings: Herodotus never names Persepolis; Diodorus, Curtius, and Plutarch are late and hostile. Use the archaeology and the inscriptions for the program itself.

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 THREE features of the Gate of All Nations built by Xerxes I at Persepolis.

Show worked solution →

A 3-mark "outline" wants three distinct, correctly named features, roughly one mark each.

Point 1: The guardian bulls: Colossal stone bulls guard the doorways: human-headed winged bulls (in the Assyrian lamassu tradition) at the western entrance, and plain, Persian-style bulls at the eastern exit.
Point 2: The trilingual inscription (XPa): Xerxes' own inscription, in Old Persian, Elamite, and Akkadian, names him as builder, records his descent from Darius I, and credits the wider program at Persepolis to father and son.
Point 3: Its function and form: It was a square four-columned hall with doorways on three sides, the monumental gatehouse through which every visitor to the terrace had to pass before approaching the king.

Markers reward three distinct, correctly named features tied to Xerxes' reign (begun after Darius I's death in 486 BC), not a single generic description of "a big gate."

foundation4 marksIdentify and briefly explain TWO structures at Persepolis that Xerxes I either completed or began.

Show worked solution →

A 4-mark "identify and explain" wants two named structures, each developed with a sentence of detail.

Structure 1: The Apadana (completed). Xerxes completed the great columned audience hall begun by his father Darius I: around 72 columns, each roughly 19 metres tall, whose north and east staircases carry the tribute-procession reliefs.

Structure 2: The Hundred-Column Hall / Throne Hall (begun). Xerxes began this vast hall for royal audiences and receiving commanders; it was left unfinished at his murder in 465 BC and completed under his son Artaxerxes I.

Markers reward two distinct, correctly named structures and an accurate statement of Xerxes' role (completing Darius's work versus beginning his own). Credit is also available for the Palace of Xerxes (Hadish) or the Gate of All Nations.

core4 marksSource A (an ExamExplained reconstruction of a Persepolis building inscription of the XPa type): 'A great god is Ahuramazda, who made this earth, who made Xerxes king. By the favour of Ahuramazda I made this Gateway of All Nations. Much else that is beautiful was built in this Parsa, which I built and which my father built.' Using Source A and your own knowledge, explain what this type of inscription reveals about how Xerxes presented his building program.

Show worked solution →

A 4-mark "explain" needs the source used and supporting own knowledge, not just paraphrase.

Use the source: Source A shows the standard formula of Xerxes' building inscriptions: it opens by crediting Ahuramazda for creation and for making Xerxes king, then claims the building as the king's own act "by the favour of Ahuramazda," and finally folds his work into his father's ("which I built and which my father built").
Own knowledge: the real texts: The genuine XPa inscription on the Gate of All Nations, and related texts such as XPf, do exactly this: they are trilingual (Old Persian, Elamite, Akkadian), stress divine sanction, and present the building program as continuous royal duty across the dynasty rather than personal vanity.
Significance: By binding construction to Ahuramazda's favour and to Darius's legacy, Xerxes presents building not as decoration but as proof of legitimate, god-supported kingship: to build Persepolis is to fulfil the role of a rightful Achaemenid king.

Markers reward correct decoding of the inscription's formula (divine sanction plus dynastic continuity) and the link to Xerxes' claim to legitimate kingship.

core5 marksSource B (an ExamExplained reconstruction of a fragment of the Apadana staircase reliefs completed under Xerxes): a delegation of robed men in soft caps carries folded textiles and leads a pair of rams, guided forward by a Persian usher whose hand rests lightly on the leading figure's wrist. Using Source B and your own knowledge, explain what the Apadana tribute reliefs reveal about the imperial ideology of Xerxes' reign.

Show worked solution →

A 5-mark "explain" needs the source used plus supporting own knowledge and a clear point about ideology.

Use the source: Source B shows the standard visual formula of the Apadana reliefs: a delegation identified by distinctive dress and regionally specific gifts (textiles and livestock), arranged in orderly procession, guided rather than driven forward by an usher's light touch on the wrist.
Own knowledge: the real reliefs: The genuine Apadana staircase reliefs, whose carving was largely completed under Xerxes, show some 23 delegations (the number commonly cited in scholarship), Medes, Elamites, Lydians, Ionians, Indians, and others, each bringing region-specific tribute to the enthroned king.
Significance: the ideology: No delegate is shown bound, kneeling under a raised weapon, or paraded as a captive, a deliberate departure from Assyrian palace reliefs of chained prisoners a century earlier. Under Xerxes, as under Darius, the reliefs present imperial rule as a harmonious, willingly maintained order of many peoples united under one king, not a realm held by force.

Markers reward correct decoding of the source's visual conventions and an explicit statement of the unity-and-consent ideology, ideally with the contrast against coercive Assyrian imagery.

core6 marksExplain the significance of the Palace of Xerxes (the Hadish) and the wider Persepolis building program as evidence for Xerxes' style of kingship.

Show worked solution →

A 6-mark "explain" needs specific evidence, developed significance, and some breadth beyond a single building.

The Hadish: Xerxes' own residential palace on the highest part of the terrace, the Hadish (an Old Persian word for palace or dwelling used in his inscriptions), was noticeably larger than his father Darius's Tachara nearby, and was reached by staircases carved with servants and attendants rather than tribute-bearers. It signals a king asserting his own monumental presence alongside, and surpassing, his father's.
Breadth of the program: Xerxes completed the Apadana, built the Gate of All Nations (XPa), began the Hundred-Column Throne Hall (finished by Artaxerxes I), and was associated with the Tripylon (the small central palace or council hall). Taken together this is a sustained, coordinated expansion of a single ceremonial complex.
Significance for kingship: The program shows Xerxes deliberately continuing and enlarging Darius's vision rather than breaking from it, presenting himself as the legitimate heir who completes the dynastic project. His inscriptions credit Ahuramazda and name his father, framing building as pious royal duty. The ceremonial terrace, used above all for the Nowruz reception of tribute, made kingship itself visible: a magnificent stage on which the empire's unity under Xerxes was performed.
Qualification: Because Susa, Babylon, and Ecbatana carried the real administration, the Persepolis program is best read as ideological and ceremonial self-presentation, not as functional government.

Markers reward precise, correctly attributed buildings, the Hadish-versus-Tachara comparison, and a clear argument about what the program reveals about how Xerxes presented himself as king.

exam25 marksESSAY. Assess the significance of Xerxes I's building program at Persepolis as an expression of Achaemenid kingship and imperial ideology.

Show worked solution →

A band-6 essay sustains a judgement on "assess," marshals precise dated evidence, and integrates historiography. This is a PLAN plus one model paragraph.

Thesis: Xerxes' building program at Persepolis was highly significant as ideology: through the Gate of All Nations, the completed Apadana with its tribute reliefs, the Hundred-Column Throne Hall, and the Palace of Xerxes, he projected a legitimate, god-sanctioned kingship over a harmonious, unified empire, and deliberately continued his father's dynastic vision. Its significance is ideological and ceremonial rather than administrative, and the archaeology corrects the hostile Greek image of Xerxes as merely a failed invader.
Argument line 1: continuity and legitimacy: Xerxes completed the Apadana begun by Darius I and adorned his father's Tachara, while his inscriptions (XPa on the Gate, XPf) credit Ahuramazda and name Darius, presenting building as continuous royal duty. The trilingual XPa, "much else that is beautiful was built in this Parsa, which I built and which my father built," frames Xerxes as the rightful heir completing the dynastic project, not an innovator.
Argument line 2: the ideology of a willing, unified empire: The Apadana staircase reliefs, largely carved under Xerxes, show some 23 delegations bringing region-specific tribute, guided by ushers rather than bound or beheaded. Margaret Cool Root (The King and Kingship in Achaemenid Art, 1979) reads this deliberate absence of violence as coordinated royal ideology: an image of consent and harmony, not a neutral record. The Gate of All Nations, through which every visitor passed, and the Nowruz tribute ceremony made that ideology a lived experience.
Argument line 3: monumental self-assertion: The Hundred-Column Throne Hall (begun by Xerxes, finished by Artaxerxes I) and the Hadish, larger than Darius's Tachara, show Xerxes asserting his own scale within his father's plan. Michael Roaf (Sculptures and Sculptors at Persepolis, 1983) shows the reliefs were produced by an organised, empire-wide workforce, itself an argument for imperial reach.
Counter-argument / qualification: The significance is ideological, not administrative: Susa, Babylon, and Ecbatana ran the empire, and Pierre Briant (From Cyrus to Alexander, 2002) cautions that the Fortification Archive documents the compulsory labour and controlled tribute behind the idealised image. The program cannot be read purely as benign harmony.
Model paragraph (line 2): The clearest measure of the program's ideological significance is what the Apadana reliefs, completed under Xerxes, choose NOT to show. Across some 23 sculpted delegations no subject is chained, kneeling under a raised weapon, or paraded as a severed head, the standard vocabulary of Assyrian palace art a century earlier. Instead a Persian usher rests a hand lightly on each leading delegate's wrist, guiding him forward with his region's gift. As Root argues, this is a constructed political fiction of willing, universal consent to Achaemenid rule, sculpted on the very staircase every dignitary climbed to reach Xerxes. The message was not that Xerxes was merely rich, but that his empire was one contented, unified order under a legitimate king.
Conclusion: Highly significant as an expression of kingship and imperial ideology, dynastic legitimacy, divine sanction, and unity through consent, but significant ceremonially rather than administratively, and always inseparable from the coercion the same empire also rested on.

Marker's note: band-6 answers ANSWER "assess," deploy precise dated evidence (XPa, the 23 delegations, the Hadish, the Throne Hall), and integrate at least two named historians (Root, Briant) as argument, using the qualification to refine rather than abandon the thesis.

exam6 marksSOURCE ANALYSIS. Assess the values and limitations of Diodorus Siculus's account (Bibliotheca Historica 17.72) of the burning of Persepolis in 330 BC as evidence for the palace complex Xerxes helped build.

Show worked solution →

A 6-mark values/limitations task needs balance, specificity, and a historian.

Origin: Diodorus Siculus wrote his Bibliotheca Historica in the first century BC, roughly three centuries after the burning, drawing on now-lost Hellenistic historians of Alexander (probably Cleitarchus), not eyewitness testimony.
Values: Diodorus, with Quintus Curtius Rufus and Plutarch (Alexander 38), preserves a tradition that the palace was lavishly decorated and immensely wealthy before the fire, indirectly corroborating the archaeological picture of gilded, richly carved halls such as the Apadana and Throne Hall Xerxes worked on. It fixes the destruction to Alexander's capture of the city in 330 BC.
Limitations: The accounts disagree on WHY the fire was set (deliberate revenge for Xerxes' burning of Athens in 480 BC, or a drunken accident), so none is reliable for motive; none describes the palace's plan or decoration in enough detail to serve as an excavation record; and all wrote to moralise about Alexander's character, not to document Xerxes' buildings.
Historian: Ernst Herzfeld and Erich Schmidt, whose 1930s Oriental Institute excavations physically uncovered the burned Apadana and Treasury, treat the literary accounts as confirming only that a fire occurred and roughly when, relying on the archaeology itself for the palace's actual appearance.

Markers reward named ancient authors, an explicit gap between literary tradition and archaeological reliability, and a historian used as argument.