Forgotten, but not unknown
Mohenjo-Daro is often described as a forgotten city, and in one sense that is fair: its ancient name, and the memory of its people, were lost long ago. But the mound itself was never hidden. Local people knew it, a later Buddhist stupa stood on top of it, and the site came to the attention of archaeologists in the early twentieth century. The story is better described as an identification, followed by a century of excavation, than as a sudden discovery.
Banerji and the first digging
The archaeologist usually credited with recognising Mohenjo-Daro is Rakhaldas Banerji (R. D. Banerji) of the Archaeological Survey of India. He visited the site around 1919-1920, was drawn by the Buddhist stupa, and began excavating in 1922. Within the stupa’s mound he found older remains beneath it, including seals and brick structures, which suggested a far earlier occupation than the Buddhist period.
This came shortly after Harappa, hundreds of kilometres to the north, had been dug by Daya Ram Sahni and others from 1921. The two sites looked alike, with matching seals and bricks, and that observation led to one of the key moments in South Asian archaeology. The finds of the Harappa discovery 1921 season and Banerji’s work together pointed to a single, previously unknown civilization.
John Marshall and the announcement
Sir John Marshall, then Director General of the Archaeological Survey of India, took charge of the Indus work. In September 1924 he published a short announcement in the Illustrated London News, appealing for comparison with other regions. Scholars of Mesopotamia replied that similar seals existed in their own collections, which helped to place the new civilization in a broader timeline.
Marshall directed large-scale digging at Mohenjo-Daro in the 1925-1926 season and later. The excavations were done in large exposures, often following walls and trenches in grid squares, and in the standards of the time they were extensive. His team included Ernest Mackay, who directed work in the late 1920s and early 1930s and published a major report. Mackay and others uncovered the Great Bath, the street plan and many objects. These later became well known, including seals, figurines, and a small bronze figure often called the “dancing girl”, although the name is a modern label.
Methods of the period were less careful than today’s. Excavation was often by arbitrary levels (called “spits”) rather than natural layers, and some records are incomplete, so later scholars have had trouble reconstructing exactly where certain objects were found. This is a good example of why tell stratigraphy and modern archaeological methods matter. Phrases such as “priest-king”, used for a carved stone head, are also old labels with little evidence behind them.
Wheeler and the postwar period
Mortimer Wheeler, who served as Director General of the Survey in the mid-1940s, turned to the Indus sites after Marshall’s era. He dug at Harappa in 1946 and returned to Mohenjo-Daro in 1950. Wheeler pioneered tighter stratigraphic methods in India, and his work added to knowledge of the citadel and defensive features.
He is also associated with the idea that invaders destroyed the cities, a claim which later research did not support. Because that debate concerns the end of the civilization rather than the dig, it is treated in our account of Indus decline theories. In brief, the skeletons found in the upper levels at Mohenjo-Daro are not evidence of a single massacre, a point made by George Dales in the 1960s.
Later work and dating
Further projects continued through the later twentieth century, including a joint effort in the 1960s and later survey and study by teams from Italy and Germany. Excavation at Mohenjo-Daro eventually slowed, partly out of concern that digging exposed fragile brick to damage. Radiocarbon dating and other techniques have since helped to place the Indus cities in the third millennium BCE, and newer work, such as ancient DNA analysis from other Indus-period sites, adds fresh questions. Radiocarbon dates at Mohenjo-Daro are relatively few, however, so exact chronologies for the city are still approximate.
The conservation problem
The same brick that has survived for thousands of years is now at risk. Several threats are commonly described:
- Salts. The ground and groundwater contain salts. They rise with moisture into the brick, crystallise, and cause the surface to flake and crumble. Salt damage is considered one of the greatest long-term problems.
- Rising groundwater. Irrigation across the Indus plain raised the water table in the twentieth century, bringing salts nearer the surface. Drainage and groundwater control measures were introduced from the 1970s onward with international help.
- Flooding and heavy rain. The site lies on a flood plain. Severe monsoon rain and floods, including in 2022, caused concern about wall damage, though the extent varies between reports.
- Weathering and visitors. Wind, rain and exposure wear exposed walls, and unrestrained access can add pressure.
Mohenjo-Daro was inscribed on the UNESCO World Heritage list in 1980. Conservation work has included capping wall tops, repairing brickwork, backfilling some excavated areas to protect them, and monitoring salt levels. None of these measures is permanent, and sustained funding and maintenance are key.
Why the history matters
The excavation history shows how a site can be both famous and incompletely understood. Most of the city remains unexcavated, the earliest layers are under water, and old digs left uneven records. The best strategy today is generally to study what has been dug, use non-invasive survey where possible, and keep the ruins stable, so that later generations can ask better questions than ours.