al-Abbas, as his successor, and Abu Ishaq was acclaimed as caliph on 9August, with the laqab of al-Mu'tasim (in full al-Mu?tasim bi'llah, "he who seeks refuge in God"). His father became the eighth Abbasid caliph of the Caliphate in 833. His father ruled the caliphate for eight years and he was succeeded by his elder son al-Wathiq.

As a young prince,