I.B. Tauris in association with the Institute of Ismaili StudiesAl-Mu'ayyad fi'l-DIn al-ShIrzI (died 470/1087), was an outstanding, multi-talented Fatimid scholar of Persian origin. He excelled as a missionary-agent, statesman, poet, preacher and theologian. Based on his autobiography, this work provides an insight into the remarkable life and achievements of al-Mu'ayyad through the important stages of his career, describing his daring attempt to win over the Buyids of western Iraq to the Fatimid cause, his dangerous flight to Cairo and finally his expedition to Syria and Iraq to build up an alliance of local rulers against the invading Saljuk Turks. The author demonstrates that in addition to being an intriguing personal account, the life of al-Mu'ayyad is a rich source of Islamic history in the 5/llth century, which deals with crucial events in the struggle between the Fatimids, Abbasids, Buyids and Saljuks for supremacy in the Muslim world.