How did the Seljuqs influence the Abbasid caliphate after taking Baghdad in 1055?

When the Seljuqs entered Baghdad in 1055, they effectively ended the century-long dominance of the Buyids and assumed control over the Abbasid caliphate. While the Seljuqs stripped the caliphs of their remaining temporal power, they officially respected the caliph’s position as the titular, spiritual leader of Sunni Islam.12

The Seljuq influence manifested in several key ways:

• Political Legitimacy: The Seljuq leader Toghril Beg was granted the title "king of the East and West" by the caliph, and later the title sultan ("authority"), formalizing a relationship where the sultan exercised independent military and political power while acknowledging the caliph’s sovereignty.23
• Sunni Restoration: The Seljuqs sought to eliminate Shi'i influence in Iraq, which had been prevalent under the Buyids, and promoted Sunni orthodoxy.2
• Institutional Support: The Seljuq vizier Nizam al-Mulk established a network of madrasahs (such as the Baghdad Nizamiyyah) to provide uniform training for administrators and religious scholars, reinforcing the state's politico-religious doctrine.42

Despite this, the Abbasid caliphs remained effectively captive to these military strongmen until the Seljuq empire began to decay, which eventually allowed later caliphs to regain some semblance of independent authority.25