Öz The Portrait of a Sultan in the Eyes of the Periphery; Yıldırım Bayezid Abstract: Sultan Bayezid I (Yıldırım Bayezid) was one of the most influential sultans, who shaped the state administration in every respect. His practises and decisions mapped out the route for the ways in which state would be governed. His reign was a period of many firsts in terms of militaristic and political developments. Despite his great achievements in Europe and Anatolia, and his decisions, which strengthened the state structure, the way the sources mentioned him is mind blowing. He, his wife and the people around him were all harshly criticized. No other Ottoman Sultan was criticized like him. As the first sultan of the transition process from beylik to statehood, how was Sultan Bayezid I seen in the eyes of nomadic Turks (‘Konar-göçer’) and neighboring Turkish beys? Was he someone who paid a heavy price for founding a state, or was he a bad ruler who deserved everything happened to him? This study is especially based on the unofficial records about him. Through these sources, it will be possible to see how the bodies constituted the periphery viewed the Sultan Bayezid I and their reasons.