Read this: The 10th century saw a mass migration of Turkic tribes from Central Asia into the Iranian plateau. Turkic tribesmen were first used in the Abbasid army as mamluks (slave-warriors), replacing Iranian and Arab elements within the army. As a result, the mamluks gained a significant political power. In 999, large portions of Iran came briefly under the rule of the Ghaznavids, whose rulers were of mamluk Turk origin, and longer subsequently under the Turkish Seljuk and Khwarezmian empires. These Turks had been Persianized and had adopted Persian models of administration and rulership. The Seljuks subsequently gave rise to the Sultanate of Rum in Anatolia, while taking their thoroughly Persianized identity with them. The result of the adoption and patronage of Persian culture by Turkish rulers was the development of a distinct Turko-Persian tradition.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What tribes migranted en masse to the Iranian plateau in the 10th Century?
Turkic tribes