The youngest brother, known as Diyā' ad-Dīn (1163–1239), served Saladin from 1191 on, then his son, al-Malik al-Afdal, and was afterwards in Egypt, Samosata, Aleppo, Mosul and Baghdad. He was one of the most famous aesthetic and stylistic critics in Arabian literature. His Kitab al-Matlial, published by the Bulaq Press in 1865 (cf. Journal of the German Oriental Society, xxxv. 148, and Ignaz Goldziher's Abhandlungen, i. 161 sqq.), contains some very independent criticism of ancient and modern Arabic verse. Some of his letters have been published by David Samuel Margoliouth On the Royal Correspondence of Diyā' ad-Dīn al-Jazarī in the Actes du dixieme congrès international des orientalistes, sect. 3, pp. 7–2 I.