Indus Valley Civilization — Key Changes

Entry	Year	Description	Impact
Early Harappan Phase	c. 3300–2600 BCE	Characterized by the development of village cultures into proto-urban settlements, fortifications, and early craft specialization. Sites like Kot Diji and Amri show the formative stages of Harappan culture.	Lays the foundation for the mature urban phase, demonstrating gradual evolution rather than sudden emergence.
Mature Harappan Phase	c. 2600–1900 BCE	The zenith of the civilization, marked by large urban centers, standardized planning, advanced drainage, extensive trade, and the widespread use of the Harappan script. This period defines the classic image of the IVC.	Represents the peak of Harappan achievements in urbanism, economy, and cultural uniformity across a vast region.
Late Harappan Phase	c. 1900–1300 BCE	A period of decline and de-urbanization, characterized by the abandonment of major cities, a decrease in standardization, and the emergence of regional cultures (e.g., Cemetery H culture, Jhukar culture).	Shows the gradual fragmentation and transformation of the Harappan cultural complex, leading to post-Harappan regional traditions.
Post-Harappan/Chalcolithic Cultures	c. 1300 BCE onwards	Successor cultures that absorbed some Harappan elements but were generally rural and less sophisticated. Examples include the Painted Grey Ware (PGW) culture and Black and Red Ware (BRW) culture.	Illustrates the continuity and discontinuity of cultural elements from the IVC into later periods, bridging to the Vedic era.