Guy now gathered a large force, committing all of his kingdom's available resources. The leadership divided on tactics. Raynald urged an offensive, while Raymond proposed defensive caution, although Saladin was besieging his castle at Tiberias. Guy decided to deal with the siege. The march towards Tiberias was arduous, and Saladin's troops overwhelmed the exhausted Frankish army at the Horns of Hattin on 4July 1187. Hattin was a massive defeat for the Franks. Nearly all the major Frankish leaders were taken prisoner, but only Raynald and the armed monks of the military orders were executed. Raymond was among the few Frankish leaders who escaped captivity. He fell seriously ill after reaching Tripoli. Within months after Hattin, Saladin conquered almost the entire kingdom. The city of Jerusalem surrendered on 2October 1187. There were no massacres following the conquest, but tens of thousands of Franks were enslaved. Those who could negotiate a free passage or were ransomed swarmed to Tyre, Tripoli, or Antioch. Conrad of Montferrat commanded the defences of Tyre. He was William's brother and arrived only days after Hattin. The childless Raymond died, and Bohemond's younger son, also called Bohemond, assumed power in Tripoli. After news of the Franks' devastating defeat at Hattin reached Italy, Pope Gregory VIII called for a new crusade. Passionate sermons raised religious fervour, and it is likely that more people took the crusader oath than during recruitment for the previous crusades.