Around 3000 BC, at the time of the Egyptian, Assyrian, and Babylonian civilizations, a highly civilized community flourished in the areas of Sindh, Baluchistan, the Punjab, Gujarat, and Rajasthan, on the banks of the river Sindhu, now called Indus. The civilization, called the Indus valley civilization, is known to be one of the most important of pre-historic settlements. Archeological excavations in Mohanjo-Daro and Harappa, which are now in Pakistan, also give evidence of the civilization.
The civilization in the Indus valley flourished for a 1000 years with their legendary town-planning, highly developed tools and weaponry, and advanced social structure and customs. Well-planned cities and buildings built of baked bricks were the main features of this civilization. The streets were at right angles and they had a thorough drainage system. The buildings were arranged according to the different layers of the society. The huge granaries and great bath were the other specialties of this settlement. Several metals such as copper, bronze, lead, and tin are known to have been used during the period.
The Indus valley people domesticated animals and the Harappans cultivated grains such as wheat and barley. Usage of cotton and woollen clothes and earthen vessels had been common. The people even had trade relationships with other civilizations and with other parts of India. There were divisions in the society according to the profession of the people. There existed a proper system of government and gods were worshipped in male and female forms. The Harappan culture slowly started declining by about 1700 BC; and repeated floods or the expansion of the desert could be the reason for their decline. It is also believed that the invasion of barbarians would have contributed to their decimation. By 1500 BC, when the Aryans arrived, the Harappan culture had almost been wiped out.