''For the time being, the crusaders had won. They set up Crusader ''states'' in the areas surrounding Jerusalem. But the Muslims were determined to regain their holy places. In 1187, a Muslim ruler and a general names Saladin launched a successfully attack on the Crusader states and recaptured Jerusalem. European kings quickly sent out a Second Crusade, the a Third until finally after the Fourth Crusade fails signed an agreement with Muslim rulers to abandon any further crusades against Jerusalem.''
So Saladin is considered a hero for launching a successful attack on the Crusader states and recaptured Jerusalem.