The news of the fall of Edessa led to a second crusade (1147-49), headed by Louis VII of France and Conrad III of Germany. In spite of the lofty motives which animated the French king, the second crusade shows a waning of the spirit of enthusiasm which had brought about the first. The political danger involved in the triumph of the Muslim arms was a determining factor in the departure of the crusading armies, and Bernard of Clairvaux, the great preacher of this crusade, found it expedient to dwell upon the taking of the cross as a potent means in gaining absolution for sin and attaining grace.
Lack of harmony between the royal leaders and the treacherous policy of the Byzantines led to irremediable disaster. The German army was almost totally destroyed in Asia Minor during the winter of 1147-48, and the other crusading host succumbed to defeat and the climate in the summer of 1148. Baldwin III by his unwise seizure of Ascalon in 1153 brought Egypt into the sphere of conflict and thus prepared the way for the fall of Jerusalem.
The Battle of Hattin in 1187 was a major setback in the fortunes of the Crusader movement, enabling the Muslims to regain control of Jerusalem from the Christians.
The battle took place near Acre, in an area whose chief geographic feature is a double hill (the "Horns of Hattin") surrounding a pass through the northern mountains between Tiberias and the road from Acre to the west.
The Darb al-Hawarnah road, built by the Romans, served as the main east-west passage between the Jordan fords, the Sea of Galilee and the Mediterranean coast. Saladin had taken Tiberias, to the east, on July 2, 1187 with only a small portion of his overall forces, largely due to infighting and confusion among the Christian forces. Raymond of Tripoli and King Guy of Jerusalem were at Acre with the bulk of the Christian army. Raymond argued that a march from Acre to Tiberias in mid-summer would be suicidal, but due to internal court politics and accusations of cowardice, King Guy ordered the army to march immediately against Saladin at Tiberias.
The Christians began their march from Sephoria on July 3, and were almost immediately under harassment from the Muslim forces. By noon on that day Saladin had joined his forces at Kafr Sabt, and sent his army to engage the Christians once they had left the spring at Turan, preventing them from retreating toward the safety of the water source. The Christians were forced to make camp in the middle of the plain, surrounded by the Muslim army, and Saladin's forces started fires around the camp during the night to make the situation worse for King Guy's army.
On the morning of July 4, the Christians broke camp and began making for the springs of Hattin, but their ragged approach was viciously attacked by Saladin's army and the Christians were annihilated; thousands were killed and the cream of the Christian army was destroyed practically at a stroke. The Muslims captured the royal tent of King Guy, as well as the True Cross, a relic sacred to the Christian forces in the Kingdom of Jerusalem. By mid-September, Saladin had taken Acre, Nablus, Jaffa, Toron, Sidon, Beirut and Ascalon, and Jerusalem fell to the Muslim army on October 2, 1187, making the beginning of the end for the Christian presence in the outremer.
News of the disastrous defeat at Hattin was the catalyst for the formation of the Third Crusade.