Although his reign was short , Nasir ad - Din Mahmud I ruled with an iron fist .
The disunity within the Seljuq realms allowed for the unexpected success of the First Crusade shortly afterwards , beginning in 1096 .
Although Seljuq 's reign was short Seljuq           I ruled with an iron fist .
The disunity within the Seljuq realms allowed for the unexpected success of the First Crusade shortly afterwards , beginning in 1096 .