mu'in ad-din was always suspicious of nur ad-din's power, but it was his policy to remain on friendly terms with his neighbours wherever possible, whether they were christian or muslim. in 1147 nur ad-din and mu'in ad-din negotiated an alliance, in which nur ad-din married mu'in ad-din's daughter ismat ad-din khatun. having established peace with aleppo, mu'in ad-din set out to besiege salkhad and bosra, after their governor, altuntash, allied with jerusalem against him. this broke jerusalem's treaty with damascus, forcing mu'in ad-din to turn to nur ad-din for assistance. nur ad-din arrived with the army of aleppo, and the crusaders were forced to withdraw; both bosra and sarkhad then surrendered to mu'in ad-din. in august 1147 mu'in ad-din was formally recognized as governor of damascus by the caliph of baghdad al-muqtafi and the seljuk sultan mas'ud, and he was also recognized formally by the fatimid caliph in egypt, al-hafiz.