When the Ayyubid Sultan Saladin laid siege to the Christian fortress of Tiberias in present-day Israel, a Christian army led by Guy of Lusignan marched to relieve the city. The ensuing Battle of Hattin led to the destruction of Guys army and the subsequent fall of Jerusalem. Within two years, Christian armies set out to avenge the defeat, leading to the Third Crusade.The Opposing CommandersThe Battle of Hattin depicting Saladin and Guy of Lusignan in personal combat, from a 13th century British manuscript by Matthew Paris. Source: Wikimedia CommonsThe opposing forces at the Battle of Hattin were led by Saladin, the Ayyubid Sultan of Egypt and Syria, and Guy of Lusignan, King of Jerusalem. Both men believed that they had a divine right to rule Jerusalem. The outcome of the battle dictated the course of events in the Holy Land for the next several decades.Guy of Lusignan was born in the French town of Lusignan in 1150 as the scion of a prominent noble family in Poitou. His family had been staunch supporters of the Catholic Churchs efforts to retake the Holy Land and his father had taken part in the Second Crusade. The date of Guys arrival in the Holy Land is not exactly known, but is believed to have been around the late 1170s. He steadily rose up the ranks of the nobility, becoming the Constable of the Kingdom of Jerusalem. In 1180, he married Sibylla, the sister of King Baldwin IV of Jerusalem.Saladin was born in 1137 or 1138 in Tikrit, in modern-day Iraq, into a Kurdish Muslim family. Raised in Syria and brought up as a Sunni Islam, he entered military service under his uncle Shirkuh, a general for the Zengid dynasty, gaining experience in Egypt where he rose to power after Shirkuhs death. By the 1180s, he united Egypt, Syria, and parts of Iraq under his rule and declared Jihad against the Crusader states.Succession Crisis in JerusalemChurch of the Holy Sepulchre, where Guy was crowned king in 1186. Source: Tourist IsraelIn the years leading up to the battle, the Kingdom of Jerusalem was embroiled in a bitter succession crisis that severely weakened its political cohesion and military preparedness. The death of King Baldwin IV in 1185, who had ruled effectively despite suffering from leprosy, set off a period of instability. Baldwin IV had appointed his nephew Baldwin V as his successor, under a regency led by Count Raymond III of Tripoli. However, Baldwin V died the following year under suspicious circumstances.His death reopened the power struggle between rival factions. One group supported Sibylla, Baldwin IVs sister and the mother of Baldwin V, who appeased her opponents by promising to divorce her unpopular husband Guy of Lusignan. After she was crowned queen, she shocked the nobles by remarrying Guy, who was crowned king at the Church of the Holy Sepulchre in August 1186.Meanwhile, Raymond of Tripoli and other nobles who favored a more cautious and diplomatic approach toward Saladin were marginalized. This deep internal division left the kingdom vulnerable. When Saladin launched his major invasion in 1187, the fractured leadership proved disastrous. The failure of the Christian nobles to unify would have a major impact on the ability of the Kingdom of Jerusalem to resist. By contrast, Saladin had pretty firm control over his caliphate when he invaded the Holy Land.The Siege of TiberiasPhotograph of the ruined Crusader fortress of Tiberias. Source: 101 IsraelBy late May of 1187, Saladin assembled the largest force he had ever commanded to date on the Golan Heights to march against the Kingdom of Jerusalem. His troops were composed of a mix of Arabs, Turkmen, Kurds, and other Muslim communities. He was reinforced by contingents of Druze warriors who resented the Crusaders because of their heavy-handed rule. His forces marched along the Sea of Galilee and surrounded the small garrison in the fortress of Tiberias. Saladin lacked the heavy siege equipment needed to reduce the garrison, but he had a plan. He hoped to draw Crusader reinforcements away from the fortresses deeper inside the country and defeat them in a pitched battle. Then his army could march on Jerusalem and Acre.Back in Jerusalem, there was a dispute between Raymond III and Guy about how to resist Saladins advance. Guy hoped to advance towards Tiberias and relieve the garrison. Raymond advised against this, claiming that it played into Saladins hands. He had support from other nobles, who believed that the Ayyubid army could not take a city by siege without heavy equipment and that he would withdraw. Nonetheless, Guy ordered a force of 20,000 men to prepare to march on Tiberias and fight Saladin.While Saladin laid siege to the city, Guy assembled his forces near the town of Sepphoris. To goad the Crusaders into marching, Saladin ordered repeated assaults against Tiberias, gradually encircling the citadel. The garrison barely held on and Guy fell for the bait, ordering his forces to march towards Saladins army. The stage was set for a major battle.Battle of Hattin Topographical map of the Horns of Hattin, 2012. Source: The History of England PodcastOwing to a lack of available fresh water, the Crusaders were tormented by thirst during the march to Tiberias. Guy of Lusignan had an estimated 18,000 infantry and cavalry with him against Saladins 40,000. Saladins men were positioned between the Crusaders and the Sea of Galilee. Before the battle, they lit the grass on fire and taunted the Crusaders, trying to entice Guys forces to advance. Meanwhile, Saladin sent light infantry and cavalry units around the Crusaders flanks in an effort to encircle the Christian forces.As Muslim archers rained arrows down on the Crusaders columns, Count Raymond led a contingent forward and managed to break through to the Sea of Galilee. However, the rest of the Christian forces were encircled and repeatedly attacked by Saladins forces. Their thirst contributed to combat exhaustion and they were no match for the Muslim army. After several attempts by Guys troops to break out, the Christian force was annihilated, with its men either being taken prisoner or being killed. Subsequently, the garrison of Tiberias surrendered.While Saladin proved merciful to many of the captured Christian nobles, including Guy, he was harsh to other groups of captives, particularly the Turcopoles (Levantine Christians serving in the Crusader armies) and the Knights Templar. Some 200 Knights were beheaded after the battle on Saladins personal orders. The remaining prisoners were sold into slavery or held in Muslim fortresses until they were ransomed. After his stunning success, Saladin ordered his forces to march south towards Jerusalem, now lightly defended following the destruction of Guys forces.The Fall of JerusalemSaladins army laying siege to Jerusalem, by Jan Luyken, 1683. Source: World History EncyclopediaThe capture of Tiberias and Guys Crusaders freed Saladins forces for an advance on Jerusalem. By mid-September, Saladin had conquered multiple towns in the Kingdom of Jerusalem, including Acre, Nablus, Jaffa, Toron, Sidon, Beirut, and Ascalon. The weakness of the Christian defenses was a reflection of Guys decision to go after Saladin with almost all of his forces. Only the city of Tyre managed to hold on after receiving Crusader reinforcements.In Jerusalem, the nobleman Balian of Ibelin tried to rally the Christian community to defend the city. Most of its garrison had been sent to fight at Hattin, meaning that the city was poorly defended. By September 20, Saladins forces arrived outside the city to find that Balian only had a small contingent of men available to fight. After repeated assaults, the Muslim army gained ground but could not take the citadel. By the end of September, Balian managed to secure a surrender agreement that allowed many of the citys residents to go free in exchange for hefty ransoms.As part of the deal, Frankish knights and their families were taken captive until they could pay their ransom. Local Christians were allowed to remain in the city and Jews were allowed to return for the first time since they had been expelled during the First Crusade. Saladins treatment of the citys population was noticeably more humane than the Crusaders and even earned him a message of congratulations from the Byzantine Emperor Isaac Angelus.The Third CrusadeMap of the Levant at the start of the Third Crusade. Source: Wikimedia CommonsThe Battle of Hattin is regarded as one of Saladins greatest battlefield triumphs. A combination of luck, guile, ruthlessness, and agility meant that he managed to draw out a formidable enemy from their fortifications and fight them on ground of his choosing. By forcing the Crusaders to fight a battle on his terms, Saladin all but guaranteed victory, and the destruction of Guys army allowed him to overrun multiple Crusader fortresses without having to lay siege to most of them.By contrast, Guy of Lusignan committed a series of mistakes when confronting the Muslim army. With little backing from the High Court of Nobles in Jerusalem, he sought to enshrine his legitimacy by defeating Saladin in a pitched battle. However, his poor strategic and tactical decision-making minimized his chances of victory. His prospects were poor once he had left the safety of Jerusalem.The loss of Jerusalem inspired the Third Crusade, during which King Richard the Lionheart of England sought to recapture Jerusalem from Saladin. When his army managed to defeat Saladin in several battles and recaptured Acre in 1191, he partly avenged the defeat at Hattin. However, Jerusalem remained out of his reach, and the reborn kingdom of Jerusalem was confined to the Levantine coast.