The First Crusade (1096-99) created four French-Christian states in the Muslim-dominated Middle East - the Kingdom of Jerusalem, the Country of Tripoli, the Principality of Antioch and the County of Edessa. But, in 1144, the Muslim ruler of Aleppo in Syria, Zengi, conquered Edessa, shocking the Christian world.
Call to arms
With Edessa's fall, Pope Eugenius III feared that all Christian territories in the Holy Land were threatened. So, aided by the great orator Abbot Bernard of Clairvaux, he convinced the French King Louis VII and the German Emperor Conrad II to launch a new Crusade, which set out in 1147.
Friends or foes?
The Crusaders marched east through Hungary into the Byzantine Empire (now Greece and western Turkey). The Byzantines were Orthodox Christians and viewed the unruly Catholic Crusaders with suspicion, offering little aid. There were many skirmishes between the two sides.
The German contingent travelled ahead of the French. To reach the Holy Land, they had to cross Muslim-held Asia Minor - a hot, hostile land. But, the Germans lacked discipline and a few days into the march were surrounded and massacred by Turkish Muslims. Their leader, Conrad, fled to join the French.
The French - with survivors from the German army - made good progress across Asia Minor, defeating a Turkish army en route. But slowed by non-combatants, they became strung out and were heavily defeated by the Turks as they neared Antioch.
The remaining Crusaders reached Antioch in 1148, where the Christian ruler, Prince Raymond, asked them to campaign against Muslim Syria in the north. Louis VII refused, perhaps because of rumours that his wife, Eleanor, was having an affair with Raymond. The Crusade headed south instead.
Disaster at Damascus
Aided by some of the Christian lords in the Holy Land, Louis VII and Conrad II attacked the major Muslim city of Damascus. But heat and lack of supplies meant that the siege was called off after just three days. Humiliated, the surviving Crusaders headed home leaving the Christian states weaker than ever.