The fifth Umayyad caliph, reigned 685-705.
Abd al-Malik spent his youth in Medina until the rebellion of Ibn al-Zubayr in 682. He left the town when the Umayyads were expelled by the rebels, but upon meeting the Syrian army advancing toward Medina, he returned with it after giving advice concerning the town and its defences. He acceded to the caliphate after the assassination of his father in 685.
Abd al-Malik faced numerous difficulties at the beginning of his reign. Although the Qaysites had been defeated by the Kalbites in 684, thus reasserting Umayyad control of Syria, Qaysites still held out in northern Iraq. The Byzantines had pushed into Anatolia, and Ibn al-Zubayr was being recognized as caliph in most parts of the empire. The governor of Kufa and Basra, who had been forced out after the death of Yazid in 683, was unable to regain control. Kufa was seized by the Shi`ite leader al-Mukhtar shortly after Abd al-Malik's accession, and Basra was held by Ibn al-Zubayr's brother, Mus`ab. Mus`ab's forces defeated al-Mukhtar in 687 and occupied Kufa.
Abd al-Malik freed himself from the Byzantine problem by making a ten-year truce with the emperor. In 690, his forces captured the rebel Qaysites. The following year Mus`ab was defeated and a Syrian army under the command of al-Hajjaj was sent to Mecca. The city was beseiged for six months; Ibn al-Zubayr was slain in 692. Al-Hajjaj was subsequently sent to Iraq to quell Kharijite uprisings, which continued there and further east until 697. The revolt of Iraqi troops under the command of Ibn al-Ash`ath in 700-701 led to al-Hajjaj's establishment of a garrison city in Iraq to house Syrian troops.
Despite these preoccupations, Abd al-Malik initiated several reforms to further centralize caliphal control. Arabic was made the official language of administration, replacing Greek and Persian; this helped to unify the tax-systems of the various provinces. Byzantine coins were replaced with a new Islamic-style coinage; the Byzantine emperor's refusal to accept this new currency caused a breakage of the truce in 692. Attributed to al-Hajjaj is the re-edition of the Uthmanic text of the Qur'an with vowel signs.
The last years of Abd al-Malik's reign were peaceful on the whole. A crisis of succession was very nearly averted: his father, Marwan, had appointed his brother Abd al-Aziz to succeed Abd al-Malik, but Abd al-Malik wished to favour his own sons. Abd al-Aziz died just five months before Abd al-Malik, and the caliphate was passed to his son Walid.