Al-Khwarizmi , Abu Ja'far Muhammad Ibn Musa

(c. 800–847) Arab mathematician, astronomer, and geographer

Al-Khwarizmi takes his name from his birthplace, Khwarizm (now Khiva in Uzbekistan). His importance lies chiefly in the knowledge he transmitted to others. Very little is known about his life except that he was a member of the academy of sciences in Baghdad, which flourished during the rule (813–33) of caliph al-Ma'mun. Al-Khwarizmi's main astronomical treatise and his chief mathematical work, the Algebra, are dedicated to the caliph. TheAlgebra enlarged upon the work of Diophantus and is largely concerned with methods for solving practical computational problems rather than algebra as the term is now understood. Insofar as he did discuss algebra, al-Khwarizmi confined his discussion to equations of the first and second degrees.

His astronomical work, Zij al-sindhind, is also based largely on the work of other scientists. As with the Algebra, its chief interest is as the earliest Arab work on the subject still in existence.

Al-Khwarizmi's other main surviving works are a treatise on the Hindu system of numerals and a treatise on geography. The Hindu number system, with its epoch-making innovations, for example the incorporation of a symbol for zero, was introduced to Europe via a Latin translation ( De numero indorum; On the Hindu Art of Reckoning) of al-Khwarizmi's work. Only the Latin translation remains but it seems certain that al-Khwarizmi was the first Arab mathematician to expound the new number system systematically. The term ‘algorithm’ (a rule of calculation) is a corrupted form of his name. His geographical treatise marked a considerable improvement over earlier work, notably in correcting some of the influential errors and misconceptions that had gained currency owing to Ptolemy's Geography.