al-Musta'sim bi'llah Zakariya ibn Ibrahim

Zakariya ibn Ibrahim ibn al-Mustamsik ibn al-Hakim, titled al-Mustasim billah, an Abbasid caliph in Cairo who held the office twice and ended deposed. ¹

Al-Suyuti says that the atabeg Aynbak al-Badri set him up as caliph in 779 AH, without an allegiance or consensus, so his first caliphate lasted fifteen days until al-Mutawakkil returned. ¹ Then Barquq gave him the allegiance after the death of his brother al-Wathiq Umar, and it continued until 791 AH. In that year Barquq regretted it, restored al-Mutawakkil and deposed Zakariya. ¹

He remained in his house until he died in deposition. ¹