There are different ways to divide the history of the Indus Valley Civilization. Archaeologists like Mortimer Wheeler split it into Early, Mature, and Late Harappan stages. Newer methods also include the Neolithic period, which covers early farming settlements, and use a stage–phase model that often combines terms from different systems.

Periodisations

The Indus Valley Civilization is often divided into three main phases: early, mature, and late Harappan. Before this civilization developed, people lived in small farming villages near rivers. When water management techniques improved, these villages grew into a connected civilization. This entire time period is sometimes called the Indus Age or the Indus Tradition.

Early studies by Sir Aurel Stein in Balochistan uncovered many ancient sites with unknown connections. After excavations at Harappa and Mohenjo Daro, some believed that people from Baluchistan moved to the Indus Valley to create the Indus Valley Civilization. However, M.R. Mughal challenged this idea by finding older settlements in the Cholistan Desert. Mughal later introduced the term "Early Harappan" in his work at the University of Pennsylvania, which combined his research across Pakistan. This classification is based mainly on sites like Harappa and Mohenjo Daro, assuming a gradual development over time. Manuel described this system as placing the Indus Valley in a three-part framework that shows the rise, peak, and decline of a society, similar to ideas proposed by Elman Service.

Coningham and Young noted that this classification became widely used because British archaeologists Raymond and Bridget Allchin supported similar divisions in their work. However, they also pointed out that this system has limits, as it focuses too much on the mature phase of the civilization.

In archaeology, a system called the Three-Age System, created by Christian Jürgensen Thomsen, divides history into the Stone Age, Bronze Age, and Iron Age. While this system helps organize museum collections, it does not fully explain the complex relationships between ancient settlements. To address this, Gordon Willey and Philip Phillips developed a method called Culture-Historical Integration, which describes how cultures are connected across time and space. Jim G. Shaffer and Diane Liechtenstein later adapted this approach for the Indus Valley.

During his research in Afghanistan, Baluchistan, Pakistan, and India, Shaffer observed that local customs in South Asia changed over time and interacted with material culture. He criticized how colonial archaeologists like Mortimer Wheeler and Stuart Piggot projected European ideas onto ancient societies. Shaffer then adapted Willey and Phillips' system for the Indus Valley, calling it the Harappan Tradition after the site of Harappa. This term refers to consistent patterns of technology and structure that remained stable over time and space.

Shaffer divided the broader Indus Valley Tradition into four eras: the pre-Harappan "Early Food Producing Era," and the Regionalisation, Integration, and Localisation eras. These roughly correspond to the Early Harappan, Mature Harappan, and Late Harappan phases. Each era can be split into smaller phases, which are groups of archaeological findings with unique characteristics. Shaffer noted that regional differences and varying cultural sequences made these eras and phases unsuitable for all sites.

Coningham and Young highlighted that Shaffer’s system replaced older terms like Mesolithic/Neolithic and Early Harappan with "Eras" to better reflect long-term changes leading to urbanization. This system also helped place sites like Mehrgarh, which are seen as ancestors to the Indus cities, within the broader Indus tradition rather than outside it.

Coningham and Young raised concerns about whether Shaffer’s definitions of Regionalisation and Localisation are clearly different enough. Shaffer himself noted that these eras share similarities, with some differences in group interactions.

The Early Food Producing Era, also called the Neolithic period, lasted from about 7000 to 5500 BCE. This era focused on food production and agriculture, with Mehrgarh Period I belonging to this time. The Regionalisation Era, from about 4000 to 2500/2300 BCE (Shaffer) or 5000 to 2600 BCE (Coningham & Young), includes the Early Harappan phase. Manuel noted that this period saw a shift in population from the uplands of Baluchistan to the floodplains of the Indus Valley. This era was rich in artistic and craft innovations, with phases like Balakot, Amri, Hakra, and Kot Diji.

The Integration Era refers to the time of the Indus Valley Civilization, when smaller cultures merged into a unified society. The Localisation Era (1900-1300 BCE) marks the breakdown of this integration, with cultural fragmentation. This era includes several phases.

Gregory Possehl divided the Indus Age into seven stages, combining older classifications, artifact descriptions, and socio-economic processes. Coningham and Young noted that Possehl’s approach is not unique, as other scholars like Singh have used similar systems that separate the Indus Valley from later traditions, making comparisons difficult.

Rita Wright used a similar framework to study the Indus Valley, influenced by Mesopotamian archaeology. She divided the period into the Early Food Producing Phase, Pre-Urban Phase, Urban Phase, and Post-Urban Phase.

Datings and alternative proposals

Rao, an archaeologist who studied the site of Bhirrana, says he found pottery called Hakra Ware in the oldest layers of the site. This pottery is believed to be from the 8th to 7th millennium BCE. Rao suggests that Bhirrana is older than the traditional dates for the Harappan civilization, but he still uses the term "Harappan" to describe it. This idea is supported by Sarkar and others in a 2016 study, which also mentions research by Possehl and radiocarbon dating from other sites. However, they note that the Mature Harappan phase ended around 800 BCE. Rao’s 2005 study and a summary by Dikshit in 2013 compare these dates with traditional timelines.

Some researchers suggest the Early Harappan Phase began around 3300 BCE, while others believe the Regionalisation Era started earlier, between 4000 BCE and 5000 BCE.

S. P. Gupta, considering new discoveries, organized the Harappan Civilization into three phases: Early, Mature, and Late. He aligned the start of the Early Harappan Phase with the beginning of the Regionalisation Era.

Most experts agree that the Integration Era, also called the Urban or Mature Harappan Phase, occurred between 2600 BCE and 1900 BCE.

Durée longue: Harappan Civilisation and Early Historic Period

Jonathan M. Kenoyer, along with Coningham & Young, describe the development of ancient India by combining the Indus Valley Civilization with the Early Historic Period. After the decline of the Indus Valley Civilization, a new focus on regional areas began, leading to the Second Urbanization of the Early Historic Period, which started around 600 BC and continued with the Maurya Empire around 300 BC.

Coningham & Young explain that many studies about early Indian urbanization have focused only on the Indus Valley Civilization or the Early Historic Period, "keeping the long separation between these two eras." This separation was first introduced during colonial times by scholars who believed "a major change in culture, language, and society occurred between the Indus Civilization and the Early Historic Period." This idea was later repeated by some scholars in South Asia after independence. Coningham & Young use Shaffer’s terms to better explain the development of urban areas in South Asia.

They suggest replacing older terms like "Chalcolithic," "Iron Age," "Proto-Historic," "Early Historic," and "Mauryan" with three new terms: "Localisation Era," "Regionalisation Era," and "Integration Era." They argue that Kenoyer’s (1998) view—that the "Integration Era" began only with the Maurya Empire around 317 BC—was too cautious. Evidence from archaeological findings shows signs of cultural and economic integration as early as 600 BC. This approach may cause disagreement among some scholars.

They also note that the term "Integration Era" might not apply to all parts of South Asia during the Mature Harappan period because "large areas in northern and southern South Asia were not affected by this regional development."