One of the great mistakes made by the Franks was the breach of the alliance in 1147 - a breach which was widened by the attack directed against Damascus during the Second Crusade; and the conquest of Damascus by Nureddin in 1154 was ultimately fatal to the Latin kingdom, removing as it did the one possible ally of the Franks, and opening the way to Egypt for the atabegs of Mosul.
Two years later Zengi died; but he left an able successor in his son, Nureddin, and an attempt to recover Edessa was successfully repelled in November 1146.
A Hugh de Lusignan appears in the illfated crusade of 110o-1101; another Hugh, the Brown, came as a pilgrim to the Holy Land in 1164, and was taken prisoner by Nureddin.
The attack was impolitic: Damascus was the one ally which could help the Franks to stem the advance of Nureddin.
The result of the failure of the Second Crusade was the renewal of Nureddin's attacks.