Al-Hajjaj ibn Yusuf (born early June AD 661 / AH 40 – AD 714 / AH 95) is a controversial Arab administrator, politician and minister of defence of the Umayyad caliphate.

Al-Hajjaj is an intelligent and tough ruler.

He has also been described as draconian, although modern historical treatments acknowledge the influence of later Abbasid historians and biographers who were opposed to the fiercely loyal and pro-Umayyad al-Hajjaj.

Al-Hajjaj bin Yousef plays a crucial role in the selection of military commanders.

He instills discipline in the soldier ranks which leads to the successful expansion of the Islamic empire to its farthest extent.

He ensures all important records are translated into Arabic, and for the first time he convinces caliph Abd Al-Malik to adopt a special currency for the Muslim world.

This leads to war with the Byzantine Empire under Justinian II.

The Byzantines are led by Leontios at the Battle of Sebastopolis in 692 and are decisively defeated.