Ibrahim ibn al-Mahdi (Arabic: إبراهيم بن المهدي) (779–839) was an Abbasid prince, singer, composer and poet. He was the son of the third Abbasid caliph Al-Mahdi. He was not a full brother of Al-Mahdi's sons Al-Hadi and Harun al-Rashid, since his mother was not Al-Khayzuran but rather an Afro Iranian princess named Shikla or Shakla. Historian Ibn Khallikan reported that Ibrahim was consequently "of dark complexion."During the Fourth Fitna, Ibrahim was proclaimed caliph on 20 July 817 by the people of Baghdad, who gave him the regnal name of al-Mubarak (Arabic: المبارك) and declared his reigning nephew Al-Ma'mun deposed. Ibrahim received the allegiance of the Hashemites. He had to resign in 819, and spent the rest of his life as a poet and a musician. He is remembered as "one of the most gifted musicians of his day, with a phenomenal vocal range."