Al-Khwarizmi (780–850) was one of the greatest Muslim scientists of the medieval period. He was simultaneously a mathematician, geographer, and astronomer. His full name was Abu Abdullah Muhammad ibn Musa al-Khwarizmi.

In his book Al-Jabr wa al-Muqabala, Khwarizmi presented the first systematic solution of linear and quadratic equations. His major achievement in algebra was solving quadratic equations with the help of squares, for which he provided geometric proofs. He was the first to present algebra as an independent branch and to discuss methods of solving equations, so Khwarizmi is called the father or founder of algebra.