Prehistoric & Proto-Historic

The Indus Valley Civilisation (c. 3300–1300 BCE)

The IVC is the world's third great Bronze Age civilisation alongside Mesopotamia and Egypt, but far larger in area — over 1.4 million sq. km at its peak, spanning present-day Pakistan and northwest India. Historians divide it into three phases: Early Harappan (pre-urban, c. 3300–2600 BCE), Mature Harappan (urban, c. 2600–1900 BCE — the phase almost all exam questions refer to), and Late Harappan (de-urbanisation, c. 1900–1300 BCE).

Major sites and what each is known for:

• Harappa (Ravi river, Punjab, Pakistan) — the first site excavated (1921, Daya Ram Sahni); gave the civilisation its name; granaries and workmen's quarters.
• Mohenjo-daro ("Mound of the Dead," Sindh, Pakistan; excavated 1922 by R.D. Banerji) — the Great Bath (a water-tight public tank, possibly for ritual bathing), the Great Granary, and the bronze "Dancing Girl" figurine.
• Dholavira (Kutch, Gujarat) — unique three-part city division (citadel, middle town, lower town) and sophisticated water-harvesting/reservoir system; a large signboard with Indus script letters.
• Lothal (Gujarat) — a dockyard, evidence of maritime trade with Mesopotamia; a fire altar and bead-making industry.
• Kalibangan (Rajasthan) — earliest evidence of a ploughed field and fire altars.
• Rakhigarhi (Haryana) — among the largest Harappan sites by area; recent DNA studies here have fed debates on Indus-population ancestry and the Aryan migration question.
• Banawali, Surkotada, Chanhudaro — smaller but exam-relevant sites (Surkotada: horse remains claimed; Chanhudaro: bead and seal-making workshops, no citadel).

Town planning: grid-pattern streets meeting at right angles, a distinct citadel (upper, for administrative/ritual buildings) and lower town (residential), burnt-brick standardised construction, covered underground drainage — arguably the most advanced sanitation of the ancient world.

Seals and script: thousands of steatite seals, usually with an animal motif (the unicorn bull is most common) and a short line of undeciphered pictographic script, read right-to-left. The script's non-decipherment remains one of archaeology's open puzzles — remember this as a stock "still unresolved" fact.

Economy and society: no clear evidence of temples, palaces, or a warrior class dominating iconography — leading many historians to describe Harappan society as relatively egalitarian and mercantile rather than despotic. Weights followed a binary system (1, 2, 4, 8…16…); trade extended to Mesopotamia (referred to as "Meluhha" in Sumerian texts).

Decline theories (asked frequently as a "which is NOT a cause" elimination question): climate change and weakening monsoons, drying up of the Ghaggar-Hakra (Saraswati) river system, tectonic shifts altering river courses, overuse of resources, and — a now largely discredited older theory — "Aryan invasion." Most modern scholarship favours gradual ecological decline and eastward population drift, not a single violent conquest.

The Vedic Period (c. 1500–600 BCE)

Divided into two sub-phases with sharply different characters — a favourite comparison-table topic.

The Later Vedic period's philosophical texts, the Upanishads, mark the beginning of speculative Indian philosophy (Brahman, Atman, karma, moksha) and directly set up the intellectual soil from which Buddhism and Jainism emerge in the 6th century BCE.