 Described by Stephen of Blois as "a city great beyond belief, very strong and unassailable", the idea of taking the city by assault was a discouraging one to the crusaders.Hoping rather to force a capitulation, or find a traitor inside the city—a tactic that had previously seen Antioch change to the control of the Byzantines and then the Seljuq Turks—the crusader army set Antioch to siege on 20 October 1097.Antioch was so large that the crusaders did not have enough troops to fully surround it, and as a result it was able to stay partially supplied.