Muḥammad ibn Mūsā al-Khwārizmī

Muḥammad ibn Mūsā al-Khwārizmī was a Persian polymath of the Abbasid era whose work in mathematics, astronomy, and geography shaped both the Islamic and the medieval European scientific traditions. Born around 780 CE, probably in Khwarezm in Central Asia, he died around 850 CE in Baghdad after a long career at the caliphal House of Wisdom.

Working under Caliph al-Ma'mūn at the Bayt al-Ḥikma, he wrote in Arabic the treatise Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa'l-muqābala, generally translated as "The Compendious Book on Calculation by Completion and Balancing". Its title gave the world the word algebra, and its systematic treatment of linear and quadratic equations established the discipline as an autonomous branch of mathematics.

A separate work, surviving only in Latin translation as Algoritmi de numero Indorum, introduced the Hindu-Arabic decimal numeral system to readers of Arabic and ultimately to Europe. The Latinised form of his name, Algoritmi, eventually entered modern languages as the word "algorithm".

He also produced an influential set of astronomical tables, the Zīj al-Sindhind, and a revised geography, Kitāb ṣūrat al-arḍ, that corrected and extended Ptolemy's coordinates for the lands of the Islamic world. His instruments and trigonometric methods circulated widely among later Arab and Persian astronomers.

The name Muḥammad is an Arabic name from the root ḥ-m-d meaning "praiseworthy" or "praised", famously borne by the Prophet of Islam. He carried it through a body of work that gave two of mathematics' most familiar terms to every language his readers could reach.