Treaty of Gallipoli

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.

On 26 July 1402, in the Battle of Ankara, the Ottoman Sultan Bayezid I was defeated and captured by Timur. This momentous event overturned the balance of power in the region, as the Ottoman domains in Anatolia were divided by Timur, who restored many of the Anatolian beyliks previously absorbed by Bayezid. Timur did not interfere with the Balkans, where the Ottoman conquest was also far advanced: before Ankara, Constantinople, almost the last remnant of the Byzantine Empire, was cut off and on the verge of falling to Bayezid. As in Anatolia, the sudden collapse of Ottoman power left a power vacuum, in which the various Christian powers of the region—the Byzantines, the Hungarians, the Republic of Venice, and a number of minor lords—each tried to secure their interests as best possible, while being too weak to actually challenge Ottoman power.

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