Al-Musta'in was the Abbasid Caliph from 862 to 866, during the "Anarchy at Samarra". After the death of previous Caliph al-Muntasir, the Turkic military leaders held a council to select his successor. They were not willing to have al-Mu'tazz or his brothers; so they elected Ahmad ibn Muhammad, a grandson of al-Mu'tasim, who took the regnal name al-Musta?in bi-llah (he who looks for help to God).

Al-Musta'in's short reign was marked by unrest, revolt, plot and counterplot as the Turkish Guard and Arab Muslims clashed over whose right it was to choose and control the caliphate. Forced to flee from the capital in 865 he had abdicated by 866 in favour of his younger brother, al-Mu'tazz, who, before the end of the year ordered his execution.

During Al-Musta'in reign, the caliphate was in serious decline. Within a comparatively short period, it became a titular post as real political power passed to Sultans, who still formally acknowledged the caliph's supremacy, rather as Christian kings in Europe looked to the politically weaker Papacy for validation of their right to rule. Yet remarkably, the caliphate continued to exist until 1924.

This is the second type of the coinage of the Caliph al-Musta’in struck in the Samarqand. Legends on both obverse and reverse citing the name of the heir, al-'Abbas.

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