India, that is Bharat, was known as Bharatvarsh to the ancient Indians. One of its western river is Sindhu, now mainly in Pakistan. The Persians, who found difficulty in pronouncing the initial s, pronounced it as H. Thus Sindhu became Hindu. The word passed from Persian to Greeks who called the river Indus and whole of the land lying this side as India and the people Indian. With the Muslim invasion the word Hindu returned to represent the land Hindustan and the people Hindu. In 1950, when India adopted its constitution, the very first article said it India, that is Bharat.

It is that western river Sindhu, along which Indus Valley Civilization prospered around 3000 BC. However, the earliest remains of a settled culture are of little agricultural villages in Baluchistan and lower Sind (both are now in Pakistan), dating back from the end of the 4th millennium BC.

Only two civilizations of the world