Abu Abdallah Mohammed ibn Musa Al-Khwarizmi (780-850) was an mathematician, astronomer, geographer and historian. His book Al-Kitab al-fi mukhtaṣar Hisab al-jabr wa-l-muqabala, The Compendious Book on Calculation by Completion and Balancing, made a significant contribution to the field of Algebra.
Al-Khwarizmi's works were influent in medieval Europe and helped encourage the scientifical studies that would led to the Renaissance.