The research aims to study an Islamic mystic personality and one of the most prominent and important Ottoman Sufi personalities in Ottoman history, the scholar Sheikh Aq Shams al-Din, who was one of the flags and sheikhs of Islam in the Ottoman Empire, and famous in his time for worldly sciences and his research in botany and medicine, as well as the link between This sheikh is one of the Ottoman sultans, Sultan Mehmed II (The Conqueror), and the task of preparing and rehabilitating this sultan and forming his personality since the early stages of his life, and explaining the impact of this education in acquiring the good fruit that the Conqueror was famous for, which is the conquest of the city of Constantinople, starting from the role of This Sheikh is preparing the Sultan Al-Fateh to make the attempt, and through the preparations, And the moral and material preparation of the battle, and finally the effective role of this sheikh in the course of the field conquest of the city. The study, in general, is a historical attempt to highlight the features of this sheikh in the various stages of his life, and to clarify the extent of the relationship and link between this great sheikh and the Ottoman Sultan Muhammad al-Fateh from his birth until his death, and to explain the impact of that relationship in the various stages of this Sultans life, and the implications of those relationships and links between him and this Sheikh. In the course of events when accompanying him to conquer the city and the emergence of the figure of the conqueror in the world arena Through the great honor he attained with the conquest of Constantinople, in order to realize the noble prophetic miraculousness, and to ratify the praise that the conqueror of Constantinople received from the Messenger of God.