Abdul Malek Ibn Marwan
Abd al-Malik ibn Marwan (646-705) was the 5th Umayyad Caliph. He was born in Mecca and grew up in Medinah. Abd al-Malek was a well-educated man and capable ruler. In his reign, all important records were translated into Arabic, and for the first time a special currency for the Muslim world was minted, which led to war with the Byzantine Empire under Justinian II. Abdul Malek became caliph after the death of his father Marwan I in 685. Within a few years, he dispatched armies, on a campaign to reassert Umayyad control over the Islamic empire. He ####first defeated the governor of Basra Mosaab Ibn al-Zubair. Abd al-Malik then appointed one of his most able generals and administrators who would later change the face of the Umayyad Empire, Hajjaj Ibn Yousef Thaqafi to march against Abd-Allah Ibn Zubayr, the caliph of Hejaz. Hajjaj's success led Abd al-Malik to assign him the role of governor of Iraq and give him free rein in the territories he controlled. Hajjaj arrived when there were many deserters in Basra and Kufa. He promptly and forcefully impelled them to return to combat.
Reforms
Abd al-Malik instituted many reforms such as: making Arabic the official language of government across the entire empire, instituting a mint that produced a uniform set of aniconic currency, expansion and reorganization of postal service, repairing the damaged Kaaba and beginning the tradition of weaving a silk cover for the Kaaba in Damascus. He also built the Dome of the Rock in Jerusalem, but parts of that city were also destroyed when Abd al-Malik's armies put down an uprising there.
Sources :
wikipedia