The most plausible and generally accepted origin of the word is Middle Persian tāzīk 'Arab' (cf. New Persian tāzi), or an Iranian (Sogdian or Parthian) cognate word. The Muslim armies that invaded Transoxiana early in the eighth century, conquering the Sogdian principalities and clashing with the Qarluq Turks (see Bregel, Atlas, Maps 8–10) consisted not only of Arabs, but also of Persian converts from Fārs and the central Zagros region (Bartol'd [Barthold], "Tadžiki," pp. 455–57). Hence the Turks of Central Asia adopted a variant of the Iranian word, täžik, to designate their Muslim adversaries in general. For example, the rulers of the south Indian Chalukya dynasty and Rashtrakuta dynasty also referred to the Arabs as "Tajika" in the 8th and 9th century. By the eleventh century (Yusof Ḵāṣṣ-ḥājeb, Qutadḡu bilig, lines 280, 282, 3265), the Qarakhanid Turks applied this term more specifically to the Persian Muslims in the Oxus basin and Khorasan, who were variously the Turks' rivals, models, overlords (under the Samanid Dynasty), and subjects (from Ghaznavid times on). Persian writers of the Ghaznavid, Seljuq and Atābak periods (ca. 1000–1260) adopted the term and extended its use to cover Persians in the rest of Greater Iran, now under Turkish rule, as early as the poet ʿOnṣori, ca. 1025 (Dabirsiāqi, pp. 3377, 3408). Iranians soon accepted it as an ethnonym, as is shown by a Persian court official's referring to mā tāzikān "we Tajiks" (Bayhaqi, ed. Fayyāz, p. 594). The distinction between Turk and Tajik became stereotyped to express the symbiosis and rivalry of the (ideally) nomadic military executive and the urban civil bureaucracy (Niẓām al-Molk: tāzik, pp. 146, 178–79; Fragner, "Tādjīk. 2" in EI2 10, p. 63).