Battle of Ankara
After the disastrous Battle of Ankara in 1402, the weakened Ottomans were forced to return the eastern coasts of Thessaly and the region of Zetounion to Byzantine rule. In 1423, however, the renewed Ottoman pressure forced the local Byzantine commander to surrender the forts of Stylida and Avlaki to the Venetians. By 1444, however, the entire region had been finally conquered by the Turks. Pteleos alone remained in Venetian hands until 1470.