It was not easy for the crusader kingdoms to maintain themselves in the East
By the 1140s, the Muslims had begun to strike back.
The fall of one of the Latin kingdoms to the Muslims led to calls for another crusade, especially from the monastic leader Saint Bernard of Clairvaux.
Bernard managed to enlist 2 powerful rulers, King Louis VII of France and Emperor Conrad III of Germany, in the 2nd Crusade.
This campaign, however, was a total failure.