Around 3300 BCE, while Mesopotamia was laying the foundations of Sumer, a parallel civilisation was flourishing along the Indus River and its tributaries in what is now Pakistan and northwest India. At its peak it covered an area larger than ancient Egypt and Mesopotamia combined — yet it remains one of history's most enigmatic cultures.
Cities of Remarkable Planning
Mohenjo-daro and Harappa, the civilisation's two greatest cities, each housed an estimated 40,000 people. Their street grids were laid out in near-perfect right angles — a feat of urban planning not matched in Europe for another 2,000 years. Houses were built of standardised fired bricks whose proportions (4:2:1) were consistent across settlements hundreds of kilometres apart.
The Great Bath and Water Engineering
At Mohenjo-daro, archaeologists uncovered the Great Bath — a large, waterproofed pool thought to have been used for ritual purification. The city's drainage system was even more impressive: nearly every house had a private bathroom connected to covered drains that ran beneath the streets. This level of sanitation was unparalleled in the ancient world.
Trade and Economy
Indus merchants traded with Mesopotamia, as evidenced by Indus-style seals found in Ur and other Sumerian cities. They exported carnelian beads, shell ornaments, timber, and possibly cotton textiles — the Indus people were among the first to cultivate cotton. Standardised stone weights suggest a sophisticated system of trade regulation.
The Undeciphered Script
Over 4,000 inscribed objects have been found, most of them small soapstone seals bearing short sequences of symbols alongside animal motifs. Despite decades of effort, the Indus script remains undeciphered. Without reading their words, we cannot know what they called themselves, who ruled them, or what gods they worshipped.
Decline and Mystery
Around 1900 BCE the great cities were gradually abandoned. Theories range from climate change and the drying of the Ghaggar-Hakra River to tectonic shifts that disrupted water supplies. There is no evidence of conquest or sudden destruction. The people simply dispersed into smaller settlements, and the civilisation faded from living memory until its rediscovery in the 1920s.
The Indus Valley Civilisation reminds us that sophistication and complexity are not the exclusive heritage of any one region — and that there are chapters of human history we have barely begun to read.
