Abu Ayyub al-Ansari
Akshamsaddin (Muhammad Shams al-Din bin Hamzah, ) (1389, Damascus – 16 February 1459, Göynük, Bolu), was an influential Ottoman religious scholar, poet, and mystic saint. He was an influential tutor and adviser to Sultan Mehmed the Conqueror. After completing his work with his master Sheikh Hacı Bayram-ı Veli, he founded the Shamsiyya-Bayramiyya Sufi order. He discovered the lost grave of Abu Ayyub al-Ansari (the companion of Muhammad) in Constantinople preceding the Siege of Constantinople.