By 2600 BCE, in the valley of the Indus and its tributaries, people were living in cities with covered drains, public wells, and granaries, centuries before comparable urban planning appears almost anywhere else in the world. The Indus Valley Civilization (sometimes called the Harappan Civilization, after the first site excavated) is one of the world's three earliest urban civilizations, alongside Mesopotamia and ancient Egypt, and by far the most extensive of the three: at its height it stretched from near the Iran-Pakistan border in the west to close to modern Delhi in the east (Encyclopaedia Britannica, "Indus civilization"[2]).
A civilization of planned cities
Archaeologists divide the civilization into three broad phases: an Early Harappan period (roughly 3300-2600 BCE) of village farming communities, a Mature Harappan period (2600-1900 BCE) when cities flourished (Encyclopaedia Britannica, "Indus civilization"[2]), and a Late Harappan period (1900-1300 BCE) of gradual decline and dispersal. Over 1,000 settlements have been identified across the Indus and the now-dry Ghaggar-Hakra river system, but two sites stand out: Mohenjo-daro and Harappa, both in present-day Pakistan, whose scale suggests they were major regional centers, possibly even twin capitals of a single state.
Mohenjo-daro, identified in 1919-20 by R. D. Banerji of the Archaeological Survey of India, is the best preserved of these cities (Archaeological Survey of India, excavation record of Mohenjo-daro[3]). It was laid out on a grid, with a raised citadel mound overlooking a lower residential town, brick houses of one and two storeys, and a public structure known as the Great Bath, a brick-and-bitumen pool nearly 12 metres long, most likely used for ritual bathing (Encyclopaedia Britannica, "Indus civilization"[2]). Beneath the streets ran covered drains that carried wastewater away from houses, and more than 700 wells supplied the city, roughly one for every three houses. Many cities would not match that level of sanitation for millennia. Bricks across the civilization's cities were made to standard ratios, and merchants used a uniform system of stone weights, suggesting some form of shared administrative or commercial authority across enormous distances.
Why has the Indus script never been deciphered?
The Indus cities traded widely: carnelian beads, ivory, and cotton textiles moved outward, while materials such as lapis lazuli came in from as far as Afghanistan, and Indus seals and goods have turned up at Mesopotamian sites, pointing to maritime and overland links with Sumer. Indus artisans and merchants used a script of short inscriptions, most often stamped onto small steatite seals alongside animal motifs, most often a unicorn-like bull (Jonathan Mark Kenoyer, Ancient Cities of the Indus Valley Civilization[4]). Despite more than a century of attempts, the Indus script has never been deciphered: no bilingual inscription comparable to the Rosetta Stone has been found, and most surviving texts are too short to test decipherment claims against. This means historians still cannot say with confidence what language the Indus people spoke (Encyclopaedia Britannica, "Indus civilization"[2]). Most specialists favor an early Dravidian-language connection, but the question is still open. No religious texts, king lists, or royal names survive to tell the story the way later Vedic texts or Mauryan inscriptions do.
Decline and legacy
By around 1900 BCE the great cities were shrinking, and by 1300 BCE urban life along the Indus had effectively ended, though rural Late Harappan communities persisted and gradually merged into other regional cultures further east and south. Cities did not return to the subcontinent until the "second urbanisation" of the Ganges plain under the Mahajanapadas in the sixth century BCE. The causes are still debated (Encyclopaedia Britannica, "Indus civilization"[2]). Leading explanations point to a weakening of the summer monsoon and the drying up of the Ghaggar-Hakra river system, which would have undercut the agriculture that fed the cities. Some scholars, though not all, identify that river with the Saraswati of the Rigveda, the oldest text of the Vedic Age that followed. Other historians emphasize shifting trade patterns or internal political change. There is no solid archaeological evidence for the once-popular idea of a violent invasion ending the civilization. With its drainage, standardized weights, and planned streets, the civilization was one of the great early experiments in city life (NCERT, Exploring Society: India and Beyond, Class 6[1]), and Mohenjo-daro sustained it for the better part of a thousand years before its streets emptied out.
