This volume aims to make Stephen of Pisa and Antioch's work on the celestial sciences accessible to a wider readership, providing not just the text but a translation and introduction as well. The edition is based on the only known manuscript of the Liber Mamonis, MS Cambrai, Médiathèque d'Agglomération, A 930. It is split into two parts: the first provides an extensive introduction to Stephen and his work, while the second features the edition and translation. A comprehensive glossary and collection of photographs of plates are also included.