the defenders before they were ready or were even aware there was a threat. This was how William de Forz captured Fotheringhay Castle in 1221. The most common practice of siege warfare was to lay siege and just wait for the surrender of the enemies inside or, quite commonly, to coerce someone inside to betray the fortification. During the medieval period, negotiations would frequently take place during the early part of the siege. An attacker – aware of a prolonged siege's great cost in time, money, and lives – might offer generous terms to a defender who surrendered quickly. The defending troops would be allowed to march away unharmed, often retaining their weapons. However, a garrison commander who was thought to have surrendered too quickly might face execution by his own side for treason. As a siege progressed, the surrounding army would build earthworks (a line of circumvallation) to completely encircle their target, preventing food, water, and other supplies from reaching the besieged city. If sufficiently desperate as the siege progressed, defenders and civilians might have been reduced to eating anything vaguely edible – horses, family pets, the leather from shoes, and even each other. The Hittite siege of a rebellious Anatolian vassal in the 14th century BC ended when the queen mother came out of the city and begged for mercy on behalf of her people. The Hittite campaign against the kingdom of Mitanni in the 14th century BC bypassed the fortified city of Carchemish. If the main objective of a campaign was not the conquest of a particular city, it could simply be passed by. When the main objective of the campaign had been fulfilled, the Hittite army returned to Carchemish and the city fell after an eight-day siege. Disease was another effective siege weapon, although the attackers were often as vulnerable as the defenders. In some instances, catapults or similar weapons were used to fling diseased animals over city walls in an early example of biological warfare. If all else failed, a besieger could claim the booty of his conquest undamaged, and retain his men and equipment intact, for the price of a well-placed bribe to a disgruntled gatekeeper. The Assyrian siege of Jerusalem in the 8th century BC came to an end when the Israelites bought them off with gifts and tribute, according to the Assyrian account, or when the Assyrian camp was struck by mass