The Wikipedia article of the day for October 15, 2019 is
Al-Mu'tadid.
Al-Mu'tadid (c. 857 – 5 April 902) was the Abbasid Caliph from 15 October 892 until his death. As a prince, he served under his father al-Muwaffaq during various military campaigns and helped suppress the Zanj Rebellion. As caliph, he restored to the Abbasid state some of the power it had lost during the turmoils of the previous decades. In a series of campaigns he recovered the provinces of Jazira, Thughur and Jibal, and effected a rapprochement with the Saffarids in the east and the Tulunids in the west. He brought the capital back to Baghdad, where he engaged in major building projects. He was a firm supporter of Sunni traditionalist orthodoxy, and notorious for his fiscal stringency and cruel punishments, but also interested in the learning and science that had flourished under his predecessors, promoting men like Thabit ibn Qurra, a mathematician and translator of Greek texts. His reign marks the last revival of the Abbasid empire before its terminal decline during the 10th century.
