Trebizond could rely on its substantial fortifications to defend itself. While solid walls protected it on all sides, and along the eastern and western walls two deep ravines augmented the defenses, parts of the city lay outside them, such as the Meydan or marketplace, and the Genoese and Venetian quarters. These walls had withstood many previous sieges: in 1223, when the city walls had not been as extensive as in the mid-15th century, the defenders had defeated a Seljuk assault; not more than a few decades earlier, Shaykh Junayd had attempted to take the city by storm, yet with only a few soldiers the Emperor John had been able to hold him off.[13]