Indus-Saraswati Civilization

The Indus-Saraswati Civilization (conventionally 'Indus Valley Civilization') was one of four great Bronze Age civilizations, alongside Egypt, Mesopotamia, and China. At its peak (~2,600–1,900 BCE), it covered over 1.5 million square kilometers — larger than Egypt and Mesopotamia combined — with 1,500+ documented sites.

Michel Danino's work tracing the Saraswati paleochannel established that more Harappan sites cluster along the dried Ghaggar-Hakra (Saraswati) course than along the Indus itself, lending weight to the 'Indus-Saraswati' nomenclature. ISRO satellite data and the 2025 multi-sensor SAR study confirmed the paleochannel's existence from the Shivalik foothills to the Rann of Kachchh.

The civilization produced the world's earliest known dock (Lothal), ploughed field (Kalibangan), public signboard (Dholavira), and urban drainage system (Mohenjo-daro). Its standardized weights and measures across hundreds of kilometers imply either centralized authority or deeply shared cultural norms — without any monumental palaces, temples, or evidence of individual rulers.

The Rakhigarhi ancient DNA (2019) showed no Steppe ancestry in a 2,500 BCE individual, confirming the IVC population was indigenous. The larger Narasimhan et al. study (523 individuals) showed Steppe-related ancestry arriving only after 2,000–1,500 BCE.

Decline came with the 4.2 kiloyear mega-drought event (~2,200–1,900 BCE) and tectonic shifts diverting the Yamuna eastward. The Saraswati ceased to reach the sea. Major urban centers were abandoned as populations migrated east into the Ganga-Yamuna doab. This was not invasion or destruction — it was climate-driven urbanization collapse.