The ancient Middle Eastern state of Mitanni (modern-day Northeast Syria, Southeastern Turkey, 2nd millennium BCE) used a dialect of Hurrian as its main language. This dialect however contains some loanwords of evidently Indo-Aryan origin, i.e. related to Sanskrit, the ancestor of many modern languages of the Indian subcontinent. The loaned vocabulary seems to be related to an elite group in Mitanni society, as they appear in the names of rulers and gods as well as in relation to horse-breeding and the military (thus forming a so-called superstrate).
It is thus generally believed that Indo-Aryan peoples settled in Upper Mesopotamia and northern Syria, and established the kingdom of Mitanni following a period of political vacuum, while also adopting Hurrian. This is considered a part of the Indo-Aryan migrations.
Linguistic context
Some theonyms, proper names, and other terminology of the Late Bronze Age Mitanni civilisation of Upper Mesopotamia exhibit an Indo-Aryan superstrate. While what few written records left by the Mittani are either in Hurrian (which appears to have been the predominant language of their kingdom) or Akkadian (the main diplomatic language of the Late Bronze Age Near East), these apparently Indo-Aryan names suggest that an Indo-Aryan elite imposed itself over the Hurrians in the course of the Indo-Aryan expansion. If these traces are Indo-Aryan, they would be the earliest known direct evidence of Indo-Aryan, and would increase the precision in dating the split between the Indo-Aryan and Iranian languages (as the texts in which the apparent Indicisms occur can be dated with some accuracy).