The Mature (Urban) Harappan phase—marked by large planned cities, standardized craft production, and long-distance exchange—began around 2600 BCE, framing the main urban florescence at Harappa and Mohenjo-daro.
Mohenjo-daro developed into a major planned urban center early in the Mature Harappan era, with a citadel/"upper" area and an extensive lower town organized on a grid-like street plan.
During the Mature Harappan period, Harappa expanded to its largest extent (over 100 hectares) and featured multiple raised, walled sectors—an urban form characteristic of Indus cities.
The Great Bath, a large brick-lined tank within the Mohenjo-daro citadel complex, dates to the 3rd millennium BCE and is widely interpreted as having served ritual bathing functions—evidence of sophisticated water engineering and public architecture.
At Harappa, the structure traditionally called the “Great Granary” on Mound F has earliest levels dating to roughly 2450 BCE. (Its precise function is debated, but it reflects large-scale planned construction within the urban center.)
By the middle of the Mature Harappan era, Mohenjo-daro’s urban fabric included extensive brick-lined drains, wells, and soak pits, demonstrating systematized civic water management integrated with street and housing layouts.
Harappa’s excavators define the Harappan Phase at the site as c. 2600–1900 BCE, encompassing the peak period of urbanism, craft specialization, and shared material culture across much of the Indus world.
Around 1900 BCE, major Indus cities (including Harappa and Mohenjo-daro) entered a transition away from large-scale urbanism, commonly treated as the end of the Mature Harappan urban phase.
In the mid-19th century, large quantities of bricks from Harappa’s ruins were removed for railway ballast (notably for the Lahore–Multan line), damaging archaeological deposits long before modern conservation standards.
Harappa’s mounds were declared protected under the Ancient Monuments Preservation Act (1904) in January 1920, enabling more systematic archaeological control of the site.
Daya Ram Sahni began major Archaeological Survey of India excavations at Harappa in January 1921, initiating systematic recovery of architecture and artifacts that helped establish the Indus civilization as a Bronze Age urban tradition.
Mohenjo-daro was discovered in 1922, and large-scale excavations began soon after (mid-1920s), rapidly revealing a vast planned city with monumental civic architecture and extensive water-management infrastructure.
The Archaeological Ruins at Moenjodaro were inscribed on the UNESCO World Heritage List in 1980, recognizing the site’s outstanding evidence for early urban planning in South Asia.
In 1986, joint Pakistani and U.S. teams began renewed multidisciplinary excavations at Harappa (the Harappa Archaeological Research Project), producing detailed new data on urbanism, craft production, and long occupational sequences.
Indus Valley Cities: Harappa and Mohenjo-daro Urban Phases (c. 2600–1900 BCE)
