The Indus River running through northwest India into Pakistan received its name from the Sanskrit term sindhu. The Persians designated the land around the Indus River as Hindu, a mispronunciation of the Sanskrit sindhu. Sanskrit word for river, sindhu. The Indus River running through northwest India into Pakistan received its name from the Sanskrit term sindhu. The Persians designated the land around the Indus River as Hindu, a mispronunciation of the Sanskrit sindhu. In 1921 archaeologists uncovered evidence of an ancientù civilization along the Indus River, which today is dated to around 3300BC and thought to represent one jùuof the largest centers of human habitation in the ancient world. The Indus Valley Civilization extend quite far from the banks of the Indus River including parts of contemporary Pakistan, Afghanistan, Iran, and India. Scholars believe that the Indus Valley Civilization had begun to decline by 1800BC, possibly due to climate change. Because of its location between the Indian Subcontinent and the Iranian plateau, the area has seen many military invasions including Alexander the Great, the Persian empire, and the Kushan empire. In 712AD, the Muslims invaded the Indus Valley. To distinguish themselves, they called all non-Muslims Hindus; the name of the land became, by default, the name of the people and their religious.