Hisham ibn Abd al-Malik
In 724, the Umayyad Caliph Hisham ibn Abd al-Malik appointed Ubayd Allah as "sahib al-kharaj", or head of taxation in Egypt. As Egyptian governors proved ineffective, Ubayd Allah became Hisham's point man and effective ruler of Egypt. Ubayd Allah secured the dismissal of Egyptian governor al-Hurr ibn Yusuf in 727, and again his successor Abd al-Malik ibn Rifa'a al-Fahmi, after they challenged his administrative powers.