He was the son of Abdallah ibn Khalid ibn Asid and belonged to the line of the Banu Umayya clan descended from Asid ibn Abi al-Is. He was based in Basra.[1] At the beginning of the Second Muslim Civil War, during which Umayyad authority had collapsed in Iraq, Khalid threw in his lot with Mus'ab ibn al-Zubayr, who had been appointed governor of Basra by his brother Abd Allah ibn al-Zubayr, the rival caliph to the Umayyads.[1]