Skip to content

Discovering the Harappan Civilisation Class 12 History

questionbuddy.in/cbse/class-12/history/bricks-beads-and-bones/discovering-the-harappan-civilisation

HistoryCBSE Class 12 · Bricks, Beads and Bones: The Harappan Civilisation

Discovering the Harappan Civilisation: Cunningham to Rakhigarhi (Class 12 History)

Updated 15 October 2026 · Fact-checked

The Harappan civilisation was discovered in stages. Cunningham reported a Harappan seal in 1875 but could not date it. Daya Ram Sahni and R.D. Banerji found seals at Harappa and Mohenjodaro, John Marshall announced a new civilisation in 1924, and R.E.M. Wheeler later introduced digging by stratigraphy.

Notice how the story moves from one puzzling seal to a named civilisation, and then to careful digging layer by layer.

Illustration drawn for QuestionBuddy.

Understand Discovering the Harappan Civilisation

Why this topic matters. Theme 1 is about how we know, not only what we know. The discovery story shows how the questions and methods of archaeologists shaped what they saw, and why interpretations change. NCERT covers it in sections 10 and 11.

1. Forgotten cities. After Harappan cities fell into ruin they were forgotten. Later people found odd objects washed up by floods, exposed by erosion, turned up by ploughing or dug up while hunting for treasure, but did not know what they were. Harappa itself was badly damaged by brick robbers: Cunningham noted that its bricks were enough for about 100 miles of railway line between Lahore and Multan. Mohenjodaro was far better preserved.

2. Cunningham's confusion (mid-nineteenth century).

  • Alexander Cunningham, the first Director-General of the ASI, often called the father of Indian archaeology.
  • Archaeologists of his time used the written word (texts and inscriptions) as a guide. His interest was the Early Historic period (c. sixth century BCE-fourth century CE) and later.
  • He used accounts of Chinese Buddhist pilgrims (fourth to seventh centuries CE) to locate sites, and collected and translated inscriptions. He recovered artefacts he thought had cultural value.
  • Harappa was not on the pilgrims' routes and was not a known Early Historic city, so it did not fit his framework. A Harappan seal given to him by an Englishman could not be placed in time (his report: 1875), because he, like many others, believed Indian history began with the first cities of the Ganga valley. He missed Harappa's significance.

3. A new old civilisation (1920s).

  • Daya Ram Sahni found seals at Harappa in the early twentieth century, in layers clearly older than Early Historic levels (excavations from 1921).
  • Rakhal Das Banerji found similar seals at Mohenjodaro (excavations from 1922), suggesting both belonged to one archaeological culture.
  • In 1924, John Marshall, Director-General of the ASI, announced a new civilisation in the Indus valley. S.N. Roy wrote that Marshall left India three thousand years older than he found her. Similar seals at Mesopotamian sites showed it was contemporaneous with Mesopotamia.
  • Marshall was the first professional archaeologist in India, with experience in Greece and Crete, and was keen on patterns of everyday life, not just spectacular finds.
  • *His flaw*: he dug in regular horizontal units across the mound, ignoring stratigraphy. Objects from different layers were grouped together, so valuable information about their context was lost for ever.

4. Wheeler's correction (1944 onwards). R.E.M. Wheeler, Director-General from 1944, saw that excavation must follow the stratigraphy of the mound rather than dig mechanically in horizontal lines. An ex-army brigadier, he brought military precision to archaeology. (Stratigraphy: the study of layers; usually the lowest is the oldest.)

5. After Partition. The major known sites went to Pakistan, so Indian archaeologists looked for sites in India: surveys in Kutch, and explorations in Punjab and Haryana. Kalibangan, Lothal, Rakhigarhi and Dholavira were discovered and excavated. Timeline points: S.R. Rao at Lothal (1955); B.B. Lal and B.K. Thapar at Kalibangan (1960); R.S. Bisht at Dholavira (1990); Amrendra Nath at Rakhigarhi (1997); Vasant Shinde's archaeogenetic research at Rakhigarhi (2013).

6. New questions and techniques. Some archaeologists seek a cultural sequence; others study why sites are located where they are or what artefacts were used for. Since the 1980s, international teams have worked jointly at Harappa and Mohenjodaro, using surface exploration and minute analysis of clay, stone, metal, plant and animal remains. At Rakhigarhi, DNA from skeletons was studied; NCERT reports that the analysis indicates the Harappans were indigenous people of the region.

7. Problems of piecing together the past.

  • *What survives*: cloth, leather, wood and reeds decay; stone, terracotta and metal survive. Broken or useless things were thrown away; intact valuables were lost or hoarded, so such finds are accidental rather than typical.
  • *Classifying finds*: by material (stone, clay, metal, bone, ivory) and, harder, by function (tool, ornament, ritual object), using resemblance to present-day objects and the context of the find (house, drain, grave, kiln).
  • *Indirect evidence*: e.g. clothing from sculpture, since only traces of cotton survive.
  • *Frames of reference*: the first seal made sense only once it had a cultural sequence and a Mesopotamian comparison.
  • *Interpreting religion* is hardest: figurines called mother goddesses, the 'priest-king', the Great Bath, fire altars at Kalibangan and Lothal, 'proto-Shiva' seals. Moving from the known (present) to the unknown (past) works for querns and pots but becomes speculative for religious symbols.

The big idea. Each generation of archaeologists asked different questions with different methods, so the picture of the civilisation grew and changed, as when George Dales's re-examination of the 'massacre' skeletons at Mohenjodaro in the 1960s reversed Wheeler's theory of an Aryan invasion.

Key quotations

Short lines worth knowing by heart: who says them, when, and why they matter.

  • Marshall left India three thousand years older than he had found her.

    S.N. Roy, The Story of Indian Archaeology (quoted in NCERT): On the 1924 announcement of the Indus valley civilisation.

    Shows how the discovery pushed back the beginning of Indian history.

  • he did not realise how old these were

    NCERT, Theme 1, section 10.1: On Cunningham and the Harappan artefacts that reached him.

    The heart of 'Cunningham's confusion'.

  • all the artefacts recovered from the same unit were grouped together

    NCERT, Theme 1, section 10.2: On Marshall's horizontal digging, which ignored stratigraphy.

    The key criticism of Marshall's method.

  • such finds are accidental rather than typical

    NCERT, Theme 1, section 11: On intact valuable artefacts that were lost or hoarded.

    A core problem of interpreting archaeological evidence.

Discovering the Harappan Civilisation: key facts

Timeline of discovery
  1. 1.1875 Cunningham's seal report
  2. 2.1921 Sahni at Harappa
  3. 3.1922 Mohenjodaro
  4. 4.1924 Marshall's announcement
  5. 5.1944 Wheeler DG
  6. 6.1946 Wheeler at Harappa
Dates from NCERT Timeline 2 and section 10.
Indian sites after Partition
1955Lothal (S.R. Rao)
1960Kalibangan (B.B. Lal, B.K. Thapar)
1990Dholavira (R.S. Bisht)
1997Rakhigarhi (Amrendra Nath)
2013archaeogenetics at Rakhigarhi (Vasant Shinde)
Kutch, Punjab and Haryana were explored.
Cunningham
First DG of ASI; guided by texts and Chinese pilgrims' accounts; Early Historic focus; could not date the seal
Believed Indian history began with Ganga valley cities.
Marshall
DG of ASI; announced the civilisation in 1924; first professional archaeologist; everyday life; dug horizontal units ignoring stratigraphy
Context of finds lost.
Wheeler
DG from 1944; followed stratigraphy; military precision (ex-brigadier)
Also argued for an Aryan 'massacre', later questioned by Dales.
Classifying finds
By materialstone, clay, metal, bone, ivory
By functiontool, ornament, ritual
Basispresent-day resemblance and context of find
Indirect evidence and frames of reference also needed.

How to answer Discovering the Harappan Civilisation questions

This topic is set as 8-mark long answers ('role of archaeologists in the discovery', 'how methods changed'), 3-mark answers (Cunningham's confusion, Marshall versus Wheeler, problems of classification) and 1-mark chronology or match items.

  1. 1Arrange the answer chronologically: Cunningham → Sahni and Banerji → Marshall → Wheeler → post-1947 work → recent research.
  2. 2For each person write three things: position, what he did, and the strength or limitation of his method.
  3. 3Use the dates from NCERT's timeline; a correct date shows precision.
  4. 4Bring in a problem of interpretation (stratigraphy, classification, religion) to show you understand method, not just names.
  5. 5Conclude that interpretations change when new methods and questions appear.

Discovering the Harappan Civilisation in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Why stratigraphy matters

Suppose you empty a dustbin that has been filled over a whole week, layer by layer, and sort everything by the hour of day when it was thrown away instead of by layer.

What would you lose, and which archaeologist made this kind of mistake?

Try it first, then show the solutionSolution
  1. Each layer of the bin belongs to one day; the top layer is the newest.
  2. Grouping by hour mixes Monday's and Sunday's rubbish, so you can no longer tell which came first.
  3. Marshall dug in uniform horizontal units and grouped finds from different layers together.

Answer: You lose the sequence and context of each item. Marshall's horizontal digging, which ignored stratigraphy, lost such context; Wheeler corrected it by following the layers.

Memory hook: Dig by layers, not by ruler.

Frames of reference

Imagine finding an old metal token with unknown writing in your grandparents' cupboard. It means nothing until you see an identical token in a museum display about a railway.

How does this resemble the story of the first Harappan seal?

Try it first, then show the solutionSolution
  1. An object needs a context to be understood.
  2. Cunningham had a seal but no frame of reference, so he could not place it.
  3. Seals found in old layers at Harappa and Mohenjodaro, and similar seals at Mesopotamian sites, gave the frame.

Answer: The seal, like the token, became meaningful only when it could be compared with other finds and placed in a cultural sequence.

Memory hook: An object speaks only in context.

Tricks to remember Discovering the Harappan Civilisation

Short memory aids. Say each one aloud once, then use it on a question the same day.

  • C-S-B-M-W: the order of discovery

    'Can Some Brave Men Win?' Cunningham, Sahni, Banerji, Marshall, Wheeler.

    Use it when: Sequence for long answers.

  • Horizontal Marshall, Vertical Wheeler

    Marshall dug in flat (horizontal) units; Wheeler followed the up-and-down layers (stratigraphy).

    Use it when: The method contrast.

  • Lothal 55, Kalibangan 60, Dholavira 90

    Read them as a running score: L-55, K-60, D-90, then R-97 for Rakhigarhi.

    Use it when: Post-Partition excavations.

Discovering the Harappan Civilisation: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Who announced the civilisation? · 1 mark · MCQBoard level

Who announced the discovery of a new civilisation in the Indus valley in 1924?
(a) Alexander Cunningham
(b) Daya Ram Sahni
(c) John Marshall
(d) R.E.M. Wheeler

Try it first, then show the solutionSolution
  1. John Marshall, as Director-General of the ASI, made the announcement in 1924 (1 mark).

Answer: (c) John Marshall

Example 2: Cunningham's confusion · 3 marks · Short answerBoard level

Why did Alexander Cunningham fail to understand the significance of Harappa? (3 marks)

Try it first, then show the solutionSolution
  1. His method relied on texts and inscriptions and on the accounts of Chinese Buddhist pilgrims to locate sites (1 mark).
  2. His focus was the Early Historic period; Harappa was not on the pilgrims' route and was not a known Early Historic city (1 mark).
  3. He believed Indian history began with the Ganga valley cities, so he could not place the seal given to him in time (1 mark).

Answer: Cunningham, the first Director-General of the ASI, used written sources and the accounts of Chinese Buddhist pilgrims of the fourth to seventh centuries CE as guides, and was interested mainly in the Early Historic period. Harappa was neither on the pilgrims' itinerary nor a known Early Historic city, so it did not fit his framework. When a Harappan seal reached him, he tried to fit it into a time-frame he knew, because like many others he thought Indian history began with the first cities of the Ganga valley. So he missed how old Harappa was.

Example 3: Chronology · 1 mark · MCQHarder board level

Arrange in chronological order:
(i) S.R. Rao begins excavations at Lothal
(ii) Excavations begin at Mohenjodaro
(iii) R.S. Bisht begins excavations at Dholavira
(iv) Wheeler becomes Director-General of the ASI
(a) ii, iv, i, iii
(b) iv, ii, i, iii
(c) ii, i, iv, iii
(d) i, ii, iv, iii

Try it first, then show the solutionSolution
  1. Mohenjodaro 1922; Wheeler 1944; Lothal 1955; Dholavira 1990 (1 mark).

Answer: (a) ii, iv, i, iii

Example 4: Marshall versus Wheeler · 3 marks · Short answerHarder board level

Compare the excavation methods of John Marshall and R.E.M. Wheeler. Why did the difference matter? (3 marks)

Try it first, then show the solutionSolution
  1. Marshall dug along regular horizontal units across the mound, ignoring stratigraphy (1 mark).
  2. Wheeler followed the stratigraphy of the mound with military precision (1 mark).
  3. Why it mattered: under Marshall, objects from different layers were grouped together and the context of finds was lost; Wheeler's method preserved the sequence (1 mark).

Answer: Marshall excavated in uniform horizontal units throughout the mound, without following its layers, so artefacts found at the same depth were grouped together even if they came from different layers. Wheeler, who became Director-General in 1944, insisted on following the stratigraphy of the mound rather than digging mechanically along horizontal lines, and brought an army officer's precision. The difference mattered because the context of a find, its layer, tells its date and associations; Marshall's method lost this information for ever, while Wheeler's preserved it.

Example 5: Source-based: a seal without a frame · 4 marks · Source-basedHarder board level

Read the source (written for this page from the NCERT account) and answer.

A collector hands an old stamp-like object of soft stone, carved with an animal and strange signs, to the head of the survey department. He records it carefully but files it with objects of a much later age, because in his view the history of the land began with the cities of a great eastern river valley. Decades later, identical objects turn up in deep, very old layers at two distant mounds, and in a far-off land beyond the sea.

(i) Identify the official and the object. (1)
(ii) Why could he not date the object correctly? (1)
(iii) How did the later finds change the understanding of the object? (2)

Try it first, then show the solutionSolution
  1. (i) Alexander Cunningham; a Harappan seal (1 mark).
  2. (ii) He believed Indian history began with the first cities in the Ganga valley, so he had no frame of reference for an older object (1 mark).
  3. (iii) Seals in old layers at Harappa (Sahni) and Mohenjodaro (Banerji) showed one older culture, announced by Marshall in 1924; similar seals at Mesopotamian sites showed it was contemporary with Mesopotamia (2 marks).

Answer: (i) Cunningham, first Director-General of the ASI, and a Harappan seal. (ii) His framework placed the beginning of Indian history in the Ganga valley cities, so the seal could not be placed in its true period. (iii) When Daya Ram Sahni and R.D. Banerji found similar seals in layers older than Early Historic levels at Harappa and Mohenjodaro, the seals were recognised as belonging to one older culture, which Marshall announced in 1924; similar seals at Mesopotamian sites then showed that this civilisation was as old as Mesopotamia.

Example 6: Long answer: archaeologists and the discovery · 8 marks · Long answerHOTS / competency

"The Harappan civilisation was not discovered in a day; each archaeologist added something and some made mistakes." Explain with reference to the roles of different archaeologists. (8 marks)

Try it first, then show the solutionSolution
  1. Introduction: forgotten cities; chance finds; brick robbers at Harappa (1 mark).
  2. Cunningham: first DG; text-based approach; Early Historic focus; 1875 seal undated (1 mark).
  3. Sahni and Banerji: seals at Harappa (1921) and Mohenjodaro (1922) in old layers; one culture (1 mark).
  4. Marshall: 1924 announcement; Mesopotamian comparison; professional approach to everyday life (1 mark).
  5. Marshall's mistake: horizontal digging lost context (1 mark).
  6. Wheeler: from 1944, stratigraphy and precision; his 'massacre' theory later questioned by Dales in the 1960s (1 mark).
  7. After 1947: Kutch, Punjab, Haryana surveys; Lothal, Kalibangan, Dholavira, Rakhigarhi; international teams since the 1980s; archaeogenetics (1 mark).
  8. Conclusion: knowledge grew through new methods and questions; interpretations were revised (1 mark).

Answer: When Harappan cities fell into ruin, they were forgotten; later people saw only strange objects turned up by floods, erosion or ploughing, and brick robbers carried off so much of Harappa that its bricks could have laid about 100 miles of railway between Lahore and Multan.

Alexander Cunningham, the first Director-General of the ASI, guided his work by texts, inscriptions and Chinese pilgrims' accounts and focused on the Early Historic period. A Harappan seal reached him (his report dates to 1875), but believing that Indian history began with the Ganga valley cities, he could not date it. In the early twentieth century Daya Ram Sahni found seals at Harappa (from 1921) in layers older than Early Historic levels, and R.D. Banerji found similar seals at Mohenjodaro (from 1922), suggesting one culture. In 1924 John Marshall announced a new civilisation, and similar seals in Mesopotamia showed it was contemporary with Mesopotamia. Marshall, the first professional archaeologist in India, studied everyday life, but his digging in uniform horizontal units ignored stratigraphy, so the context of many finds was lost.

R.E.M. Wheeler, Director-General from 1944, corrected this by following the layers with military precision, although his claim that invading Aryans massacred the people of Mohenjodaro was later questioned by George Dales in the 1960s. After Partition, Indian archaeologists searched Kutch, Punjab and Haryana, excavating Lothal (1955), Kalibangan (1960), Dholavira (1990) and Rakhigarhi (1997); since the 1980s, international teams have analysed every scrap of evidence, and archaeogenetic research at Rakhigarhi began in 2013.

The discovery was thus a long process: each generation asked new questions and used better methods, and some earlier interpretations had to be reversed.

Where students lose marks in Discovering the Harappan Civilisation

The slips examiners see most often, and what to write instead.

  • Mistake: Crediting Cunningham with the discovery

    He is the first big name in the chapter.

    Wrong working

    Cunningham discovered the Harappan civilisation in 1875.

    Right working

    Cunningham reported a Harappan seal in 1875 but did not realise its age; Marshall announced the civilisation in 1924.

    Do this: Separate 'saw a seal' from 'recognised a civilisation'.

    Usually costs: 1-2 marks.

  • Mistake: Reversing Marshall's and Wheeler's methods

    Both were Directors-General.

    Wrong working

    Marshall followed stratigraphy; Wheeler dug in horizontal units.

    Right working

    Marshall dug horizontal units ignoring stratigraphy; Wheeler followed stratigraphy.

    Do this: Horizontal Marshall, Vertical Wheeler.

    Usually costs: 1-2 marks.

  • Mistake: Listing names without contributions

    Long answers need evaluation.

    Wrong working

    Cunningham, Sahni, Banerji, Marshall and Wheeler discovered Harappa.

    Right working

    For each: what he did, and a strength or limitation of his approach.

    Do this: Three lines per archaeologist: post, work, method.

    Usually costs: Up to 4 of 8 marks.

  • Mistake: Wrong dates

    Several close dates.

    Wrong working

    Marshall announced the civilisation in 1944.

    Right working

    Marshall: 1924. Wheeler became Director-General in 1944.

    Do this: 1924 announcement, 1944 Wheeler: twenty years apart.

    Usually costs: 1 mark.

Exam tips

  • Asked in: 2024 board paper 61/1/1 Q28(b) (8 marks, role of archaeologists in the discovery of Harappa); 2025 board paper 61/7/1 Q28(b) (8 marks, how archaeologists' roles and methods shaped our understanding); 2023 board paper 61/3/1 Q31 (4-mark source on how artefacts are identified). Answers here are our own.
  • A chronological structure with dates scores well in an 8-mark answer.
  • Always add one limitation (Cunningham's framework, Marshall's horizontal digging) and one correction (Wheeler, Dales).
  • Mention post-1947 work and Rakhigarhi to show you know the recent part of NCERT's timeline.

Practice questions on Discovering the Harappan Civilisation

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

  1. Q1 · 1 mark · MCQBoard level

    Who was the first Director-General of the Archaeological Survey of India?
    (a) John Marshall
    (b) Alexander Cunningham
    (c) R.E.M. Wheeler
    (d) Daya Ram Sahni

    Hint

    Father of Indian archaeology.

    Answer

    (b) Alexander Cunningham.

  2. Q2 · 2 marks · Very short answerBoard level

    Why was Mohenjodaro better preserved than Harappa, although Harappa was found first? (2 marks)

    Hint

    Railway bricks.

    Answer

    Harappa was badly destroyed by brick robbers: Cunningham noted that its bricks could lay about 100 miles of the railway line between Lahore and Multan. Mohenjodaro escaped such damage.

  3. Q3 · 3 marks · Short answerHarder board level

    Explain two ways in which archaeologists classify their finds, with an example each. (3 marks)

    Hint

    What it is made of; what it was for.

    Answer

    By material: stone, clay, metal, bone or ivory, for example a chert weight is stone. By function: tool, ornament, ritual object or more than one; this is harder and is judged by resemblance to present-day objects (querns, beads, pots) and by the context of the find, such as whether it lay in a house, drain, grave or kiln.

  4. Q4 · 3 marks · Short answerHarder board level

    How did the Partition of 1947 change the direction of Harappan archaeology in India? (3 marks)

    Hint

    Where were the big sites?

    Answer

    The major known sites, Harappa and Mohenjodaro, became part of Pakistan. This spurred Indian archaeologists to look for sites within India: surveys in Kutch and explorations in Punjab and Haryana found many settlements, and Kalibangan, Lothal, Rakhigarhi and Dholavira were discovered and excavated. The frontiers of the civilisation had nothing to do with modern borders.

  5. Q5 · 1 mark · Assertion-reasonHarder board level

    Assertion (A): Valuable intact artefacts found at Harappan sites may not represent everyday life.
    Reason (R): Such objects were usually lost or hoarded and never retrieved.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.

    Hint

    Accidental, not typical.

    Answer

    (a) Both true; because intact valuables survive only when lost or hoarded, such finds are accidental rather than typical.

  6. Q6 · 3 marks · Short answerHOTS / competency

    Suppose an archaeologist identifies a conical stone as a linga only because similar stones are worshipped today. Evaluate this method of moving from the known to the unknown. (3 marks)

    Hint

    Querns versus religious symbols.

    Answer

    Moving from the present to the past is reasonable for everyday objects such as querns and pots, whose use is clear from their form. For religious symbols it becomes speculative, because beliefs and meanings change over millennia; similarity of shape does not prove similarity of meaning. The identification is possible but must be treated as a hypothesis and checked against context, such as where the stone was found.

  7. Q7 · 4 marks · Short answerHOTS / competency

    "Interpretations in archaeology can be reversed." Illustrate with the debate over the skeletons at Mohenjodaro. (4 marks)

    Hint

    Wheeler versus Dales.

    Answer

    In 1947 Wheeler linked skeletons found at Mohenjodaro with the Rigveda, which calls Indra the fort-destroyer, and suggested that invading Aryans massacred the people. In the 1960s George Dales re-examined the evidence and showed the skeletons did not belong to the same period; most came from careless burials, and there was no destruction level, burning or sign of a last defence of the citadel. A careful re-examination of data thus reversed an earlier theory, and recent DNA studies at Rakhigarhi also question large-scale migration.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

  1. 1.In which year did Marshall announce the new civilisation?Show answer

    1924.

  2. 2.Who found seals at Mohenjodaro?Show answer

    Rakhal Das Banerji.

  3. 3.What sources did Cunningham use to locate early sites?Show answer

    Accounts of Chinese Buddhist pilgrims, plus texts and inscriptions.

  4. 4.What was the flaw in Marshall's excavation method?Show answer

    He dug in uniform horizontal units, ignoring stratigraphy, so context was lost.

  5. 5.When did R.S. Bisht begin excavating Dholavira?Show answer

    1990.

  6. 6.Name two ways of classifying finds.Show answer

    By material and by function.

Discovering the Harappan Civilisation: frequently asked questions

Who discovered the Harappan civilisation?

It was a step-by-step discovery. Daya Ram Sahni and R.D. Banerji found seals at Harappa and Mohenjodaro, and John Marshall announced the new civilisation in 1924. Cunningham had seen a seal earlier but could not date it.

What is Cunningham's confusion?

Cunningham relied on texts and pilgrims' accounts and thought Indian history began with Ganga valley cities, so he could not place the Harappan seal he received in its true period.

What did Wheeler change in Indian archaeology?

He insisted on excavating according to the stratigraphy of the mound instead of in mechanical horizontal units, and brought military precision to fieldwork.

Why is Harappan religion hard to reconstruct?

Because archaeologists must infer beliefs from objects such as figurines, seals and structures, often by comparison with later traditions, which is speculative for religious symbols.