In the early-Harappan stage, the people lived in large villages in the plains. There was a gradual growth of towns in the Indus valley. Also, the transition from rural to urban life took place during this period. The sites of Amri and Kot Diji remain the evidence for early-Harappan stage.

In the mature-Harappan stage, great cities emerged. The excavations at Kalibangan with its elaborate town planning and urban features prove this phase of evolution.

In the late-Harappan stage, the decline of the Indus culture started. The excavations at Lothal reveal this stage of evolution. Lothal with its port was founded much later. It was surrounded by a massive brick wall as flood protection. Lothal remained an emporium of trade between the Harappan civilization and the remaining part of India as well as Mesopotamia.

Date of the Harappan Culture

In 1931, Sir John Marshall estimated the duration of the occupation of Mohenjodaro between 3250 and 2750 B.C. Subsequently, as and when new sites were discovered, the dating of the Harappan culture is modified. The advent of the radiocarbon method paves way for fixing almost accurate dates. By 1956, Fairservis brought down the dating of the Harappan culture to between 2000 and 1500 B.C. on the basis of radiocarbon dates of his findings. In 1964, D.P. Agarwal came to the conclusion that the total span of this culture should be between 2300 and 1750 B.C. Yet, there is further scope of modification of these dates.

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