Great Seljuk Empire

The Great Seljuk Empire was a state ruled by a dynasty descended from the Oghuz Turkish tribes. It dominated the central Middle East during the 11th century and controlled territories stretching from Central Asia to eastern Anatolia. The dynasty took its name from Seljuk ibn Duqaq, a tribal leader whose family migrated into the Islamic lands.

The Seljuk state system combined Turkish military tradition with Persian administrative practice. The Sultan held formal political and military authority, while the Abbasid Caliph in Baghdad retained symbolic religious authority. Persian was the language of administration and culture, while Arabic remained the language of religious learning.

Foundation and Early Expansion

The Seljuk rise began in Khurasan, where they competed with the Ghaznavids. The Ghaznavid defeat at Dandanaqan in 1040 opened Iranian territories to Seljuk expansion. In 1055, Tughril Beg entered Baghdad and assumed a protective role against other powers contending for Iraq. Subsequently, Alp Arslan and Malik-Shah extended Seljuk borders to the west and east.

Manzikert and Anatolia

The Battle of Manzikert in 1071 took place in eastern Anatolia between the forces of Alp Arslan and those of the Byzantine Empire under Romanos IV Diogenes. The Byzantine defeat and the capture of the emperor enabled Turkmen tribes to settle in Anatolia. This gave rise to a new independent state, the Sultanate of Rum, centered in the eastern region.

Administration and Economy

The most celebrated vizier of this period was Nizam al-Mulk, who wrote a political treatise (Siyasat-nama) describing how the Sultan should govern. As the chief administrator, he established a higher school called the Nizamiyya madrasa, which trained scholars and state officials. Military expenses were funded through the iqta' system, whereby officers received the right to collect taxes from land in place of a cash salary. A new calendar was also created, based on astronomical science, with participation from scholars including Omar Khayyam.

Fragmentation and End

After Malik-Shah's death in 1092, the succession was divided among his sons and their supporters. The atabeg system—in which a military officer acted as regent for a young amir—later spawned independent regional states. Sanjar was the last powerful Sultan of the east, and after his defeat by the Qara-Khitai at the Battle of Qatwan in 1141, his death in 1157 saw Khurasan fragment into competing powers. Seljuk territories passed to new rulers, notably the Khwarazmian shahs, while the Anatolian branch continued until the 13th century.