Social and political developments in Iran in 420s And 430s (AH)، conincided with the ineptness of the Buwayhid (Ale Boye)، the expansion in the activities of the Ismailis، arrivals of the Turkmen and Ghaz Bedouins in the East Of Iran and their confrontation with the Ghaznavids. After the Seljuk Tugrul’s coming to power، The Abbasid caliph، Al-Qaem، decided to recognize the Seljuk groups. According to the theory of the emirate ascendency that had been proposed by Maverdy، if a person took control of a territory by force، they could gain the caliph’s approval only if they met certain requirements. Yet، the misdemeanor of the Sejuk forces in the course of the invasion of Islamic cities next to their actions in the course of their presence in Baghdad had led the public as well the caliph to believe that Tygrul was not least competent to be delegated the state. Yet، Maverdi had offered a solution to this problem suggesting that in case of incompetence، the caliph could assign a deputy (Nayebi) in his place so that the deputy’s competence might counteract the incompetence of the could-be governor. Accordingly، acknowledging Amidolmolk Kandari، Tugrul’s minister، as his deputy، the caliph tried to justify the delegation of the state to Tugrul. Utlizing methods of a historical research and applying Maverdi’s theory، the present article aims at investigating the essence of the the Seljuk’s rise to power against the Buwayhid (Ale Boye).