In 1403, Süleyman was in Gallipoli negotiating with a number of Christian states (Byzantium, Genoa, Venice, Knights Hospitaller and Naxos) in the Balkans in order to secure an agreement with them and start an offensive against his brothers in Asia Minor. The terms of the agreement were that Byzantium was to cease being a vassal of the Ottoman, while in the territorial sense, regain Thessaloniki and a number of cities on the coast of the Bosphorus and Black Sea. One of the provisions of this contract referred to Stefan, although he probably did not take part in its conclusion. Stefan kept his former possessions, but had to still pay tribute and send the Sultan support militarily, although he was not obliged to lead them himself.