The History of India begins with the birth of the Indus Valley Civilization, more precisely known as Harappan Civilization. It flourished around 2,500 BC, in the western part of South Asia, what today is Pakistan and Western India. The Indus Valley was home to the largest of the four ancient urban civilizations of Egypt, Mesopotamia, India and China. Nothing was known about this civilization till 1920s when the Archaeological Department of India carried out excavations in the Indus valley wherein the ruins of the two old cities, viz. Mohenjodaro and Harappa were unearthed. The ruins of buildings and other things like household articles, weapons of war, gold and silver ornaments, seals, toys, pottery wares, etc., show that some four to five thousand years ago a highly developed Civilization flourished in this region.