Mehmed I, also called Çelebi Sultan Mehmed (died May 26, 1421, Edirne, Ottoman Empire) Ottoman sultan who reunified the dismembered Ottoman territories following the defeat of Ankara (1402). He ruled in Anatolia and, after 1413, in the Balkans as well.

Timur (Tamerlane), victorious over the Ottoman sultan Bayezid I at the Battle of Ankara, restored to the Turkmen their principalities that had been annexed by the Ottomans and divided the remaining Ottoman territory among three of Bayezid’s sons. Thus, Mehmed ruled in Amasya, İsa in Bursa, and Süleyman in Rumelia (Balkan lands under Ottoman control). Mehmed defeated İsa and seized Bursa