Muḥammad ibn al-ʿAbbās Abū Bakr al-Khwārazmī, better simply known as Abu Bakr al-Khwarazmi was a 10th-century Iranian poet and secretary, who throughout his long career served in the court of the Hamdanids, Samanids, Saffarids and Buyids. He is best known as the author of the early encyclopedia (“Key to the Sciences”) in the Arabic language.