Al-Qa'im

Abū Ja'far Abdallah ibn Aḥmad al-Qādir (Arabic: أبو جعفر عبد الله بن أحمد القادر), better known by his regnal name al-Qā'im bi-amri 'llāh (Arabic: القائم بأمر الله, lit. 'he who carries out the command of God') or simply as al-Qā'im; 8 November 1001 – 3 April 1075), was the Abbasid caliph in Baghdad from 1031 to 1075. He was the son of the previous caliph, al-Qadir. Al-Qa'im's reign coincided with the end of the dominance of Buyid amirs over the Caliphate and the rise of the Seljuk sultans.

Source: Wikipedia — https://en.wikipedia.org/wiki/Al-Qa'im_(Abbasid_caliph_at_Baghdad)