The Treaty of Gallipoli, concluded in January or early February 1403, was a peace treaty between Süleyman Çelebi, ruler of the Ottoman territories in the Balkans, and the main Christian regional powers: the Byzantine Empire, the Republic of Venice, the Republic of Genoa, the Knights Hospitaller, and the Duchy of Naxos. Concluded in the aftermath of the Battle of Ankara, while Süleyman tried to strengthen his own position in the succession struggle with his brothers, the treaty brought major concessions to the Christian states, especially the Byzantines, who regained lost territories and achieved a position of nominal superiority over the Ottoman ruler. Its provisions were honoured by Süleyman as well as by Mehmed I, the victor of the Ottoman succession struggle, but collapsed after Mehmed's death in 1421.