Cryptanalysis treatise written for the Ayyubid emir al-Ashraf Musa of Damascus. Its main technical contribution is the cryptanalysis of monoalphabetic space-free cryptograms (al-mudmaj), developed to evade Al-Kindi's techniques — part of an arms race between codemakers and codebreakers. It also introduces the concept of minimum sample size for frequency analysis. In the West, this type of cryptanalysis is not documented until the 16th century (Giambattista della Porta). Ibn Adlan was also a linguist and grammarian; poetry was part of his literary training, not his main occupation.