Diophantus was one of the outstanding mathematicians of his era but almost nothing is known of his life and his writings survive only in fragmentary form. His most famous work was in the field of number theory and of the so-called Diophantine equations named for him. His major work, the Arithmetica, contained many new methods and results in this field. It originally consisted of 13 books but only 6 survived to be translated by the Arabs. However Diophantus was not solely interested in equations with only integral (whole number) solutions and also considered rational solutions. Diophantus made considerable innovations in the use of symbolism in Greek mathematics – the lack of suitable symbolism had previously hampered work in algebra.