he defeat of the Turks by the Mongols at the battle of Ankara in 1402 and the riots that broke out in the Ottoman state immediately afterwards, postponed the fall of the Byzantine Empire for almost half a century. Byzantium, however, was to weak to take advantage of the situation in order to regain its strength. The only thing it succeeded in doing was to recover Thessalonike, certain areas on the Black Sea and the Sea of Marmara, as well as the islands of Skiathos, Skopelos and Skyros. It also became involved in the conflicts which arose among the Turks, siding with Mehmed I, who, in his turn, maintained good relations with Byzantium throughout the entire period of his reign.

Manuel II availed himself of the opportunity offered by the temporary halt of the Turkish invasions to absent himself from his capital for a while. After a short stay in Thessalonike, he went on to the Peloponnese in the spring of 1415, in order to help strengthen the Despotate. There he was introduced to the ideas of the neo-Platonic philosopher, George Gemistos Plethon, regarding the reform of the state. While in the region, he also rebuilt the wall of the Hexamilion at the Isthmus of Corinth, and prepared the ground for the final conquest of the principality of Achaia.