In 843-4, during the caliphate of al-Wathiq (r. 842–847), he was arrested as part of a general purge of the secretaries and was punished with a fine and flogging, but he was subsequently released and allowed to retain his office.
[3] Under al-Mutawakkil (r. 847–861), he became the chief secretary for the caliph's son and second heir al-Mu'tazz, and was also appointed as the vizier 'Ubaydallah ibn Yahya's deputy over the Department of Taxation (diwan al-kharaj).
[6] After Muhammad ibn 'Abdallah agreed to sue for peace, Ahmad served as a leading member of the delegations sent to negotiate the terms of surrender, which resulted in al-Musta'in being deposed in January 866.
In late 866 al-Mu'tazz attempted to remove Wasif al-Turki and Bugha al-Sharabi, two generals who had sided with al-Musta'in during the civil war, from power, but the caliph was forced to reverse his decision when the army protested this action, and after negotiating with the two men, Ahmad restored them to their positions.
[12] Despite this, al-Mu'tazz and Ahmad continued in their efforts to destroy the officers, and they succeeded in having Bugha killed in 868, which, combined with Wasif's death the previous year, resulted in the influence of the military being temporarily reduced.