During the reign of Kusaila its territory extended from the region of modern-day Fez in the west to the western Aurès and later Kairaouan and the interior of Ifriqiya in the east.
dˈʊɹɹɪŋ ðə ɹˈeɪn ʌv kjuːsˈeɪlə ɪts tˈɛɹɪtˌoːɹi ɛkstˈɛndᵻd fɹʌmðə ɹˈiːdʒən ʌv mˈɑːdɚndˈeɪ fˈɛz ɪnðə wˈɛst tə ðə wˈɛstɚn ˈɔːɹəz ænd lˈeɪɾɚ kˌaɪɹeɪˈɑːjuːən ænd ðɪ ɪntˈɪɹiɚɹ ʌv ˈɪfɹɪkˌɪjə ɪnðɪ ˈiːst.