 When al-Muhallab reached Basra after arriving from Mecca on his way to Khurasan, the leader of the Tamim, al-Ahnaf ibn Qays, proclaimed to the Basran garrison and its Zubayrid governor, al-Harith ibn Abi Rabi'a al-Makhzumi, that "only al-Muhallab" was capable of defeating the Azariqa.After al-Muhallab refused their initial entreaties, the Basran nobles forged a letter from Ibn al-Zubayr calling on him to abandon his assignment to Khurasan and confront the Kharijites instead, which he accepted after securing assurances of loyalty from the troops and sufficient funds from the provincial treasury.The campaign against the Kharijites "was to occupy him [al-Muhallab], on and off, for the next thirteen years", according to Crone.