The Battle of Montgisard was fought between the Ayyubids and the Kingdom of Jerusalem on November 25, 1177. The 16 year old King Baldwin IV, seriously afflicted by leprosy, led an out-numbered Christian force against the army of Saladin. The Islamic force was routed and their casualties were massive, only a fraction managed to flee to safety.
In 1177, the Crusader kingdom was facing the prospect of a succession crisis. King Baldwin IV was a leper and could not leave an heir. His sister Sibylla had been left widowed and pregnant by William of Montferrat, and the nobles of the kingdom began to seek another suitable husband. At the same time, Philip of Alsace, Count of Flanders, arrived on pilgrimage, and demanded that Sibylla be married off to one of his vassals. Philip and Baldwin also planned an alliance with the Byzantine Empire for a naval attack on Egypt; but none of these plans came to fruition.
Meanwhile, Saladin planned his own invasion of the kingdom from Egypt. Learning of Saladin's plans, Baldwin IV left Jerusalem with, according to William of Tyre, only 375 knights to attempt a defense at Ascalon, but Baldwin was stalled there by a detachment of troops sent by Saladin, who, again according to William of Tyre, had men. Accompanying Baldwin was Raynald of Chatillon, lord of Oultrejordain, who had just been released from captivity in Aleppo in 1176. Raynald was a fierce enemy of Saladin, and was the effective commander of the army, with King Baldwin too ill to command it personally. Also with the army were Odo de St Amand, master of the Knights Templar, Baldwin of Ibelin, his brother Balian, Reginald of Sidon, and Joscelin III of Edessa. Another Templar force attempted to meet Baldwin at Ascalon, but they were also besieged at Gaza.
Saladin continued his march towards Jerusalem, thinking that Baldwin would not dare to follow him with so few men. He attacked Ramla, Lydda and Arsuf, but because Baldwin was supposedly not a danger, he allowed his army to be spread out over a large area, pillaging and foraging. However, unknown to Saladin, the forces he had left to subdue the King had been insufficient and now both Baldwin and the Templars were marching to intercept him before he reached Jerusalem.
The Christians, led by the King, pursued the Muslims along the coast, finally catching their enemies at Montgisard near Ramla. Saladin was taken totally by surprise. His army was in disarray, out of formation and tired from a long march. The Islamic army, in a state of panic, scrambled to make battle lines against the enemy. However, in the distance, the Christian army was completely quiet. King Baldwin ordered the relic of the True Cross to be raised in front of the troops. The King, whose teenage body was already ravaged by aggressive leprosy, was helped from his horse and dropped to his knees before the cross. He prayed to God for victory and rose to his feet to cheers from his army. As Saladin's army rushed to prepare, Baldwin began the charge across the sand.
The Jerusalem army smashed into the hurriedly arranged Muslims, inflicting huge casualties. The King, fighting with bandaged hands to cover his terrible wounds and sores, was in the thick of the fighting and Saladin's men were quickly overwhelmed. They tried to flee but hardly any escaped. Saladin himself only avoided capture by escaping on a racing camel.
King Baldwin's victory was total. He had utterly destroyed the invasion force, captured Saladin's baggage train and killed his nephew, (Taqi ad-Din's son) Ahmad.
Baldwin pursued Saladin until nightfall, and then retired to Ascalon. Deluged by ten days of heavy rains and suffering the loss of roughly ninety percent of his army, including his personal bodyguard of Mamluks, Saladin fled back to Egypt, harassed by Bedouins along the way. Only one tenth of his army made it back to Egypt with him.
Saladin, fearing the tenuousness of both his hold on Egypt and the alliance with his Syrian vassals, spread propaganda that the Christians had in fact lost the battle; Baldwin likewise propagandized his victory. He erected a Benedictine monastery on the battlefield, dedicated to St. Catherine of Alexandria, whose feast day fell on the day of the battle. However, it was a difficult victory; Roger des Moulins, master of the Knights Hospitaller, reported that men had been killed and 750 returned home wounded.
Meanwhile, Raymond III of Tripoli and Bohemund III of Antioch joined with Philip of Alsace in a separate expedition against Harim in Syria; the siege of Harim lasted into 1178, and Saladin's defeat at Montgisard prevented him from relieving his Syrian vassals. Despite an intervening year of relative peace, by 1179 Saladin was able to renew his attacks on the kingdom, including his victory at the Battle of Marj Ayyun that year. This led to almost another decade of warfare which culminated in Saladin's crushing victory over the Crusaders at the Battle of Hattin in 1187.
An account of the battle is also given in Swedish author Jan Guillou's novel Tempelriddaren (The Knight Templar) (ISBN 91-1-300733-5), in which the protagonist, Arn Magnusson (de Gothia) is portrayed as a high ranking member of the Knights Templar, commanding a contingent of the army at the battle of Montgisard.