Final answer:
The Indus Valley civilization was invaded by the Aryans who brought their social and religious systems, including the Vedic religion, between 200 -1500 BCE.
Step-by-step explanation:
The Indus Valley civilization declined around 1700 BCE, possibly due to environmental factors such as deforestation and soil degradation. After the decline of the Indus Valley civilization, the region was invaded by a group of nomadic Indo-European speakers known as the Aryans. These Aryans brought their social and religious systems, including the Vedic religion, to the region between 200 -1500 BCE.
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