The Indus Valley Civilisation

The civilisation was revealed in 1921 at Harappa by Dayaram Sahni and in 1922 at Mohenjo-daro by R.D. Banerji, under the direction of John Marshall. It covered more than a million square kilometres — larger than Egypt and Mesopotamia combined — stretching from Sutkagendor on the Makran coast to Alamgirpur in the east and Manda in Kashmir to Daimabad in Maharashtra. Its Mature Phase ran roughly from 2600 to 1900 BCE.

Over 1,400 Harappan sites are known, most of them in India and Pakistan along the Indus and the now-dry Ghaggar-Hakra (often identified with the Saraswati). Major sites include Harappa, Mohenjo-daro, Chanhu-daro, Kalibangan, Lothal, Banawali, Rakhigarhi and Dholavira.

Harappan cities were planned on a grid, with a raised citadel to the west and a lower town below, built from standardised burnt bricks. Mohenjo-daro's Great Bath — a watertight brick tank — and the covered street drains of Harappan towns have no parallel in the ancient world. The granary at Mohenjo-daro, the dockyard at Lothal, and the water reservoirs of Dholavira show an extraordinary mastery of hydraulic engineering.

Uniform systems of weights (in ratios of 1:2:4:8…) and measures, wheeled carts, and a still-undeciphered script found on steatite seals point to a tightly organised commercial society — though whether it was ruled by kings, merchants or priestly councils remains debated.

The economy rested on two-crop agriculture, cotton cultivation (the Harappans were among the earliest cotton growers) and vigorous trade. Harappan seals discovered in Mesopotamia, where the land was called Meluhha, prove direct sea trade with West Asia by about 2350 BCE. crafts — bead-making, shell work, bronze casting by the lost-wax method — were highly specialised.

Religious life emerges from images: the Mother Goddess, the famous Pashupati seal showing a horned figure surrounded by animals (a possible proto-Shiva), animal worship, and reverence for the peepal tree. No grand temples have been found; worship seems to have been domestic and civic.

By about 1900 BCE the great cities decayed. Older theories blamed an Aryan invasion, but no evidence of violence or conquest has survived. Scholars today point to climate change, the drying of the Ghaggar-Hakra river system, floods and the collapse of trade as the likely causes of a gradual de-urbanisation. Harappan communities did not vanish; they dispersed eastward into the Ganga plains, carrying elements of craft, worship and farming into later Indian culture.