India's civilisation birth
Indian civilisation began as early as 2500 BCE. People, during the c. 3000 BCE live in the hills but moved to the Indus Plain as there were fertile soil there. The Indus people soon learned how to control and redirect water by building dams in the Indus River.
Government
Historians think that there must have been a system of efficient government as Mohenjo-daro was well planned. The Mohenjo-daro was build c. 2600 BCE and abandoned around 1900 BCE. It was rediscovered in 1922 by Rakhaldas Bandyopadhyay, an officer of the Archaeological Survey of India. It is located in the Sindh province on a Pleistocene ridge in the middle of the flood plain of the Indus River. Such examples are the Citadel, Drainage System , Granary and The Great Bath.
Artefacts of the Mohenj
o-daroThe "Dancing girl", found in 1926 from a house in Mohenjo-daro, was about 4500 years old. It is a 10.8 cm long bronze statue.
Occupations
Most of the people were farmers who grow crops.
Some of them become priests,who conducted religious ceremonies for religious bathing. (The Great Bath)
Writing
Thousands of stone seals were found in Indus, 
which might be a form of identification for the Indus people.
So far, nobody can understand what is written on the stone seals.
Decline of the Indus Valley Civilisation
C. 1500 BCE, the Indus Valley Civilisation rapidly declined. Mohenjo-daro and Harappa were soon abandoned. The causes of its decline are not certain. However, Archaeologits have noticed progressive deterioration in the construction of buildings nearer the surface. This indicates the decline might be due to Indus floods. Irrigation systems were destroyed and mosquitoe's breeding could have caused malaria.
Aryans
About 1500 BC, India was invaded by Indo-European people. These people came from the area between the Black Sea and the Caspian sea. The Aryans first settled along the Indus River, in the same place where the Harappa people had lived. They settled down and mixed with the local Indian people. They lived there from about 1500 BC to about 800 BC. About 800 BC, the Aryans learned how to use iron for weapons and tools. Once the Aryans learned how to use iron, they used their new weapons to conquer more of India, and moved to the south and east into the Ganges river valley. They settled there not long after 800 BC.