Considering Custom in the Making of Siyar(Islamic International Law)

Custom is a source of Islamic law in general and Siyar (Islamic international law) inparticular. Islamic jurists have set out the elements and conditions of customs forgeneral jurisprudential purpose. However, no one has, to the authors’knowledge,formulated them from Siyar perspective. This paper is an attempt to fill this gap bytracing two important elements of an international custom, namely frequent anddominant general practice of States, and acceptance of that practice as law. These twowill constitute a valid custom provided they fulfill certain conditions, most importantly that the custom must not conflict with Shari’ah or the spirit of Shari’ah.