The Muslim world united following the Second Crusade. Meanwhile, the Christian universe remained splintered. Factions particularly degraded the Christian community in the Holy Land. In-fighting and ignorance allowed the Muslims to defeat a large Christian force at Hattin. Afterward, Saladin and his Islamic armies swept through the region and capture Jerusalem. Pope Gregory VIII could not allow the desecration of Jerusalem and declared a Third Crusade to free the holy city from the Muslims.
The Second Crusade ended in 1149 in Christian defeat. The Europeans squabbled and failed to conquer Damascus. Nur-ad Din Zangi controlled the city and extended his reach throughout Syria. His nephew, Saladin, helped unite through force and guile much of the Muslim world. However, the Crusaders checked Saladin at Montgisard in 1177.
By the 1180s, the Muslim threat was obvious to the Christians controlling Jerusalem. King Guy hoped to remain at peace while others, including the Knights Templar, wanted to eliminate the threat. The Crusaders lost a decisive engagement at Hattin in 1187. Most of the survivors were executed. King Guy was ransomed and eventually returned to Christendom. Other survivors were sold into slavery.
As Guy awaited his salvation, Saladin went on the offensive. He captured Acre and then laid siege to Jerusalem. By the end of 1187, Saladin took the holy city from the Christians. Pope Urban III died after hearing about the defeats at Hattin and Acre. His successor, Gregory VIII, did not have time to respond. Jerusalem fell before he could act.
Pope Gregory VIII declared a crusade to liberate Jerusalem. He claimed the loss was a result of Christian sins across Europe. England’s Henry II and France’s Philip II immediately ended their war. Henry died quickly thereafter leaving his son, Richard I, to take up the cross. The archbishop of Canterbury recruited soldiers for King Richard. Meanwhile, Holy Roman Emperor Frederick Barbarossa marched almost immediately. European relief finally arrived two years after the Battle of Hattin. The Second Crusade began in earnest in 1189.
Christian incompetence and infighting led to the debacle at Hattin. Afterward, Muslims aggressively conquered Christian lands including Acre and Jerusalem. Europe responded, organized, marched to recapture Jerusalem, and reinforce their brethren in the Holy Land. The Third Crusade lasted three years before the Europeans returned home, but they never recaptured the Holy City.