Yasyan got very little support from Seljuk governors and Ridwan in forming a united front to defend Antioch from the army of the First Crusade thus he sought help from Duqaq.
But because of jealousies between the Seljuk governors and the anarchy in the main sultanate after the death of Malik-Shah, he got very little support. When the news about the approaching army of the First Crusade reached Antioch, Yagsyan tried to form a united front to defend Antioch. Over the winter of 1097-1098, Antioch was besieged by the Crusaders, and Yagsiyan sought help from Duqaq. Even Ridwan, whose domain was next to Antioch, sent only a small number of troops. 
