In 977 CE, Sabuktigin, a Turkic governor under the Samanids, established the Ghaznavid dynasty in Ghazna (modern-day Afghanistan), which lasted until 1186.^[34] The Ghaznavids expanded their empire by annexing Samanid territories south of the Amu Darya in the late 10th century, eventually occupying parts of Eastern Iran, Afghanistan, Pakistan, and north-west India.The Ghaznavids are credited with introducing Islam to predominantly Hindu India, initiated by ruler Mahmud's invasions starting in 1000. However, their power in the region waned, especially after Mahmud's death in 1030, and by 1040, the Seljuqs had overtaken Ghaznavid lands in Iran.^[36]

The Seljuqs, of Turkic origin and Persianate culture, conquered Iran during the 11th century.^[34] They established the Sunni Muslim Great Seljuq Empire, extending from Anatolia to western Afghanistan and the borders of modern-day China. Known as cultural patrons, they significantly influenced Persian art, literature, and language, and are seen as the cultural forebears of the Western Turks.

Tughril Beg, the founder of the Seljuq dynasty, initially targeted the Ghaznavids in Khorasan and expanded his empire without destroying conquered cities. In 1055, he was recognized as King of the East by the Baghdad caliph. Under his successor, Malik Shah (1072–1092), and his Iranian vizier, Nizam al Mulk, the empire experienced a cultural and scientific renaissance. This period saw the establishment of an observatory where Omar Khayyám worked and the founding of religious schools.^[34]

After Malik Shah I's death in 1092, the Seljuq Empire fragmented due to internal disputes among his brother and sons. This fragmentation led to the formation of different states, including the Sultanate of Rûm in Anatolia and various dominions in Syria, Iraq, and Persia. The weakening of Seljuq power in Iran paved the way for the rise of other dynasties, including a revitalized Abbasid caliphate and the Khwarezmshahs, a Sunni Muslim Persianate dynasty of East Turkic origin. In 1194, the Khwarezmshah Ala ad-Din Tekish defeated the last Seljuq sultan, leading to the collapse of the Seljuq Empire in Iran, except for the Sultanate of Rûm.