How long have Indo-Aryan languages been spoken in northern India and Pakistan?

Indo-Aryan languages have been spoken in what is now northern India and Pakistan since before 1000 BCE.1

While the precise date of entry into the Indian subcontinent cannot be determined, it is generally accepted that Indo-Aryan speakers migrated into the region from the northwest during the late 3rd and 2nd millennia BCE, with the beginning of the 2nd millennium BCE being a plausible timeframe. The earliest literary evidence of these languages is found in the Rigveda, which dates to approximately 1500 BCE.23

Modern scholarship characterizes this process as a series of migrations rather than an invasion. Although some scholars maintain that Indo-Aryans originated within the subcontinent, the prevailing linguistic evidence supports the thesis that they arrived from an external homeland.23