Al-Muhtadi, Muslim caliph

Abū Isḥāq Muḥammad ibn Hārūn ibn Muḥammad ibn Hārūn al-Muhtadī bi-ʾLlāh, better known by his regnal name al-Muhtadī bi-ʾLlāh, was the Caliph of the Abbasid Caliphate from July 869 to June 870, during the "Anarchy at Samarra".

A caliphate is an institution or public office under the leadership of an Islamic steward with the title of caliph, a person considered a political–religious successor to the Islamic prophet Muhammad and a leader of the entire Muslim world (ummah). Historically, the caliphates were polities based on Islam which developed into multi-ethnic trans-national empires.