Minhaj as-Sunnah an-Nabawiyyah

منهاج السنة النبوية

A major theological and historical work written as a refutation of the Shia theologian Ibn al-Mutahhar al-Hilli. Ibn Taymiyyah defends Sunni positions on the Companions, the caliphate, and creedal issues, while also critiquing aspects of Ash'ari and Mu'tazili theology. It is one of the most important Sunni polemical works.