Indus Valley (Harappan) Civilization

The Indus Valley Civilisation, also called the Harappan Civilisation after its first-excavated city, was one of the three earliest urban civilisations of the ancient world, alongside Mesopotamia and Egypt.

Its mature urban phase flourished from around 2600 to 1900 BCE across the floodplains of the Indus and Ghaggar-Hakra rivers in what is now Pakistan and northwestern India, covering a vast area of roughly a million square kilometres, larger than its Mesopotamian and Egyptian contemporaries. Rather than a centralised empire, it appears to have been a remarkably uniform civilisation spread across hundreds of settlements, including the major cities of Harappa and Mohenjo-daro. These cities astonish modern observers with their advanced urban planning: streets laid out on grid patterns, standardised fired-brick construction, sophisticated covered drainage and sewage systems, public baths such as the Great Bath of Mohenjo-daro, and large granaries. The Harappans used standardised weights and measures across their territory, indicating coordinated administration and extensive internal and long-distance trade, including documented contact with Mesopotamia. They produced fine craftwork in beads, pottery, metals, and seals, the last often carved with animal motifs and an as-yet undeciphered script, whose inability to be read leaves much of their political organisation, religion, and social structure uncertain. Notably, the civilisation left little evidence of grand palaces, large-scale warfare, or monumental tombs, suggesting a society organised differently from the militarised states to its west. From around 1900 BCE the cities went into decline, with populations dispersing toward the east and south. The causes are debated but likely include climate change and weakening monsoons, the drying and shifting of major rivers, and resulting disruption to agriculture and trade, leading to a gradual transformation rather than a sudden collapse.