Unur, ruler of Damascus, had been allied with Jerusalem against the threat of Zengi. Now, an alliance between Nur ad-Din and Unur had been made, by marrying Unur's daughter. The crusaders, along with King Baldwin III of Jerusalem and Melisende, agreed to attack Damascus. The crusaders had set up camp in a well-watered earlier, but were later convinced to move towards the city so that they could have a more direct attack. This left them exposed and without water, and they were forced to retreat.