Abd al - Malik ibn Salih Abd al - Malik ibn Salih ibn Ali ( , " Abimelech " , in Greek sources ; 750 – 812 CE ) was a member of the Abbasid dynasty who served as general and governor in Syria and Egypt . He distinguished himself in several raids against the Byzantine Empire , but his great influence and authority in Syria caused Caliph Harun al - Rashid to imprison him in 803 . Released in 809 , he was dispatched in 812 by Caliph al - Amin to gather troops against his brother al - Ma ' mun in the ongoing civil war between the two brothers , but died of an illness . Biography . Abd al - Malik ' s family were among the most powerful clans during the early Abbasid era . They played an important role in the final overthrow of the Umayyads in Syria , which thereafter became their particular power base . He was the nephew of Abdallah ibn Ali , the first Abbasid governor of Syria , and a son of Salih ibn Ali the first Abbasid governor of Egypt and successor of Abdallah in Syria after the latter staged a failed uprising in 754 . Abd al - Malik ' s elder brothers al - Fadl ibn Salih and Ibrahim ibn Salih also served as governors in Syria and Egypt . From his father ' s side , he was a cousin of Caliphs al - Saffah ( r . 750 – 754 ) and al - Mansur ( r . 754 – 775 ) . His mother was one of the concubines of the last Umayyad Caliph , Marwan II ( r . 744 – 750 ) . After Marwan ' s death , she was bought by Salih . Some sources alleged that she was already pregnant at the time , which would mean that Abd al - Malik was a son of Marwan II . Under Harun al - Rashid ( r . 786 – 809 ) , Abd al - Malik held his first major commands : from circa 789 to 793 , he was governor of the strategically critical " jund Qinnasrin " and of the newly created " jund " of " al - ' Awasim " , which comprised the Caliphate ' s borderlands with the Byzantine Empire . From this position , he led expeditions into Byzantine Asia Minor in 790 / 791 and possibly also in 792 / 793 , when his son Abd ar - Rahman captured the fortress of Thebasa . In 792 , after the death of Ibrahim , Abd al - Malik became the head of his clan , and in 794 he was appointed as governor of the province of Damascus , with his brother Abdallah ibn Salih succeeding him in the border . During the next couple of years , he also served briefly as governor of Medina and Egypt , but he was soon back on the Byzantine frontier : in late 797 he raided into Cappadocia and Galatia as far as Ancyra , where he received an embassy from Empress Irene of Athens ( r . 797 – 802 ) which asked for a peace agreement , but was rebuffed . In 798 , he led another campaign that reached and plundered the great Byzantine army base and imperial stable s at Malagina in Bithynia . He carried off much booty , including the imperial parade horses and baggage - train . On his return , he was attacked by the forces of the themes of Opsikion and Optimatoi , but defeated them . At the same time , his son raided the city of Ephesus . In circa 800 , Abd al - Malik was also placed as tutor over Harun ' s son al - Qasim . His prominence and influence with the army made Harun distrust him and in 803 he was arrested and thrown into prison . The actual reason remains unclear , although most sources agree that his own son , Abd ar - Rahman , informed the Caliph that he was allegedly planning to overthrow him . Abd al - Malik remained imprisoned until Harun ' s death six years later , when the Caliph al - Amin ( r . 809 – 813 ) released him . Amin ' s succession was contested by his elder half - brother al - Ma ' mun , and there was unrest in Syria . Abd al - Malik still wielded considerable influence over the frontier troops , and therefore he was appointed governor of Syria and Upper Mesopotamia and tasked with securing these regions for Amin and raising troops to confront Ma ' mun . Soon after reaching his seat at Al - Raqqah , however , Abd al - Malik fell ill and died . His grave was demolished a few years later by the victorious Ma ' mun , allegedly because Abd al - Malik had sworn never to accept Ma ' mun ' s rule .