The central portion of the Indus Valley is the earliest focal point of historic civilization in India, dating from the late fourth millennium BCE.

The Early Harappan Ravi Phase of Indus Valley Civilization, named after the nearby Ravi River, begins in circa 3300 BCE; it will last until 2800 BCE.

It is related to the Hakra Phase, identified in the Ghaggar-Hakra River Valley to the west, and predates the Kot Diji Phase (2800-2600 BCE, Harappan 2), named after a site in northern Sindh, Pakistan, near Mohenjo Daro.