The advanced #Harappan civilization which flourished between 2500-1500 BCE, reached a stage of stagnation by 1500 BCE.
Around this time the #Aryans  began to arrive in India in several waves

They came into conflict with the indigenous inhabitants called the dasas and the dasyus and took over their lands

The Aryans entered India in stages and took several centuries to bring India under their control. 
They first settled in the #SaptaSindhu region(the land of 7 rivers). They named it #Brahmavarta (land of the gods)
The period between 1500BCE and 1000BCE during which they lived here is known as the Early/Rig Vedic period

The Aryans gradually moved ahead and settled in the #Gangetic Valley. The entire region under their control was renamed #Aryavarta (land of Aryans). This period of their settlement between 1000BCE and 600BCE during which they lived in the Gangetic Plains is called as the Later Vedic period
#Harappan #Aryans