The speakers of Iranian languages may have migrated into that part of Asia as early as 1500 B.C. Presumably they were originally a nomadic tribe who filtered down through the Caucasus to the Iranian plateau. They apparently subjugated peoples already there and mingled with them, but their dominance of particular areas is recorded in the place names Parsua and Parsumash. The Assyrian rulers were by the 9th cent. B.C. sending expeditions against them, and the recurrence of those campaigns is evidence of the strength of the early Persians.
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