Süleyman Çelebi was an Ottoman prince and a co-ruler of the Ottoman Empire for several years during the Ottoman Interregnum. There is a tradition of western origin, according to which Suleiman the Magnificent was "Suleiman II", but that tradition has been based on an erroneous assumption that Süleyman Çelebi was to be recognised as a legitimate sultan.

The Battle of Ankara or Angora was fought on 20 July 1402 at the Çubuk plain near Ankara, between the forces of the Ottoman sultan Bayezid I and the emir of the Timurid Empire, Timur. The battle was a major victory for Timur, and it led to the Ottoman Interregnum.