Abu al-Fadl al-Abbas ibn Muhammad[a] (c. 1390–February or March 1430), commonly known as al-Musta'in II,[b] was the 10th "shadow" Abbasid caliph of Cairo, reigning under the tutelage of the Egyptian Mamluk sultans from 1406 to 1414.
Unable to choose a candidate from among themselves, the quarreling Mamluks followed the advice of Faraj's son Fath Allah, who had suggested appointing al-Musta'in as sultan.
The Mamluk realms were divided, with Nawruz al-Hafizi receiving the Syrian provinces and al-Musta'in returning to Egypt accompanied by Shaykh al-Mahmudi and Baktamur Djillik.
Baktamur Djillik's death on 15 September accelerated Shaykh's usurpation of power, which became complete when he had himself recognized as sultan on 6 November 1412, whereupon he assumed the title of al-Mu'ayyad.
[4] According to 15th-century historian al-Suyuti, al-Musta'in remained in the Mediterranean city until the reign of Sultan Sayf ad-Din Tatar, when he was released and allowed to return to Cairo.
[1] Nevertheless, al-Musta'in's position as caliph was recognized far beyond Egypt's borders, with distant rulers such as Ghiyasuddin Azam Shah of Bengal sending him large sums of money.