One of the important elements which provided Selim I with the preliminaries of comprehensive military attack against the territory of Mamlū ks, was the bringing together of the Madrasa educators, the jurisprudents (Mufties) and the Ilmiye class elders. In examining the issue of Ottoman invasion against the Mamlū ks, although it is referred to the Ulema and Muftis’ permission to fight with the Mamlū ks, it often does not pay close attention to the complexity of the issue of this fatwas (legal opinions) and the considerations of the Madrasa educators and jurisprudents in this matter. This study shows that, according to the Mulla Arab’ s fatwa, the Sheikh al-Islam during the reign of Bayazid II, on the illegitimacy of two Muslim rulers’ conflicts that, led to the end of the Ottoman-Mamlū ks five-year wars, also because of the Mamluk Sultans were Sunni, declaring Jihad against them was simply not possible. Knowing this, by the conventional way in asking the fatwa, Selim I made a request for fatwa about the legitimation of the military attack against Mamlū ks vaguely and without reference to the case consciously and deliberately. Considering all the problems ahead in issuing the Fatwa of jihad against the Sunni Mamlū k rulers, The Madrasa educators and the Muftis issued a multi-stage fatwas. These fatwas, on the one hand, realized the objective purpose of the Ottoman Sultan to attack on the Mamluks, and on the other, in appearance, there was no contradiction with the Mulla arab’ previous fatwa.