Abu'l-Husayn Muhammad ibn Ali (Arabic: أبو الحسين محمد بن علي), better known by his nickname Akhu Muhsin (أخو محسن),[1] was a 10th-century anti-Isma'ili writer.
[2] Based to a large degree on the previous anti-Isma'ili tract of Ibn Rizam, which now survives only in fragmentary form, he composed his own treatise against the Fatimid Caliphate and their Isma'ili adherents c. 980,[1][3] at a time when the Fatimids were trying to expand their rule over Syria and conquer Damascus.
[1][2] From the fragments, it appears that Akhu Muhsin's work contained separate parts dealing with history and doctrine.
[3] Indeed, the work introduced extensive quotations from an anonymous tract, the Kitāb al-siyāsa ("Book of Methodology" or "Book of the Highest Initiation"), which purported to be an Isma'ili work describing methods of winning new converts and initiating them into the secrets of the Isma'ili doctrine.
[5] Ibn Rizam and Akhu Mahsin's account thus "provided the basis for most subsequent Sunni writing", notably the public denunciation of the Fatimids in the Baghdad Manifesto of 1011, sponsored by the Abbasid caliph al-Qadir.