A distinguished scholar, author and statesman, al-Mu'ayyad fi'l-Din al-Shirazi (1000-1078 CE) lived during one of the most turbulent periods in Islamic history. The 11th-century was characterized, among other things, by an acute struggle for supremacy between the Sunni and Shi'a braches of Islam, represented politically by the 'Abbasid and Fatimid caliphates. Al-Mu'ayyad was originally a Fatimid missionary; but his outstanding intellectual and literary skills eventually gained him important positions in the Fatimid administration. Eventually he attained the highest ranks in the religious hierarchy, and won widespead acclaim for his scholarship and sagacity. The Diwan , the work here translated, is notable for its exceptional poetic quality and covers a wide range of facinating political and religious issues, from al-Mu'ayyad's intellectual disputations to devotions in praise of the Prophet Muhammad and his family. This first complete English translation seeks to recapture some of the poetic power and flavour of one of the undoubted masterpieces of medieval Arabic literature.