Answer
Al-Hajjaj ibn Yusuf was Abd al-Malik's viceroy in Iraq. He was a skilled general and administrator who played a key role in consolidating the Umayyad Caliphate. Al-Hajjaj was responsible for suppressing the rebellion of Abd al-Rahman ibn Muhammad ibn al-Ash'ath, which threatened the stability of the Umayyad dynasty. He also expanded the Umayyad empire by conquering new territories in Central Asia and India.