In October 1178, King Baldwin IV of Jerusalem and the Knights Templar began building the castle of Chastellet at the site of Jacob's Ford, the only crossing place of the Jordan River and the main route from Saladin's Empire to the Kingdom of Jerusalem. The castle was only a day's march away from Damascus, Saladin's capital, and would severely undermine his authority there. At the beginning of construction Saladin was away quelling a rebellion in Lebanon. The castle was set to rival the size of Crac des Chevaliers but when Saladin returned, only the castle's first ring of walls was finished, standing ten metres high and only one tower was completed with the rest of the castle still unfinished.
In the Spring of 1179 several skirmishes took place, mainly with Saladin victorious. Baldwin retreated to Tiberias and later Jerusalem to regroup, while Saladin summoned reinforcements from northern Syria and Egypt. By August 1179 Saladin was ready to assault Jacob's Ford. Baldwin was now stationed at Tiberias, only a half-day's march away. Saladin began by bombarding the castle with arrows from the east and west and then sending specialist miners to sap the walls by filling a tunnel under the wall with brush and setting a fire to cause the roof to collapse bringing the wall down with it. The tunnel was completed on the fourth day of the siege but the fire failed due to the tunnel not being directly under the wall. Saladin was now expecting Baldwin to arrive soon and force his retreat so he needed to continue the sapping immediately but with the fire still raging it was now impossible. Saladin offered a gold coin for each man who volunteered to put the fire out which they did by carrying buckets of water from the Jordan river. The volunteers suffered heavy casualties due to the Crusaders concentrating their fire on them in an attempt to buy time for Baldwins arrival. With the fire out, the tunnel was extended and set afire again on the fifth day causing a breach through which Saladin poured his men, killing 800 of the garrison and taking a further 700 captive who he then had executed. Saladin ordered his men to fill the castle well with the bodies of slain men and horses, spoiling the water source for many years to come and deterring reconstruction on the site. Baldwin arrived six hours later and, seeing his castle in flames, turned back. Saladin dismantled the castle, but not before a "plague" ravaged his army killing ten of his commanders.