At the death of Emperor Basil II (1025), much of Eastern Anatolia had been brought back under the control of Constantinople. Friendly relations with Venice and Rus’, combined with the decline of the Abbasid Caliphate and the Carolingian Empire, allowed for an aggressive foreign policy and the revival of Byzantine power. However, this strengthening proved to be short-lived, as the many conquests of the Bulgar-slayer left the empire in a state of overstretch, leading to its inability to manage the new territories and ultimately weakening it in the long term.

It was in this context that the Seljuk Turks, originally from Central Asia, arrived at the gates of Anatolia in 1045.

The phenomenon of nomadic raids in Asia Minor had already begun in 1016 and intensified between the second and third decades of the 11th century. Many nomads fled westward in the face of the advancing Seljuks from the East. The Seljuks, as noted, arrived in the region only in the 1040s, and it is likely that their first direct clashes with the Byzantines occurred at the end of that decade in the Caucasus region.

The Seljuk advance culminated in 1071 when Sultan Alp Arslan defeated the troops of Emperor Roman IV near Manzikert (now Malazgirt, Turkey). It was a decisive victory, followed by the Turkish conquest of Anatolia, a fertile region central to Byzantium from a fiscal perspective. Furthermore, at Manzikert, the Eastern Roman Empire demonstrated its inability to defend territories too far from its capital.

After the events of 1071, the Seljuks defeated the Byzantines once again in Asia Minor (1072) and later conquered Aleppo, Antioch (1074), and Nicaea (1075).

A factor that favored the Turkish expansion in Anatolia was the harsh assimilationist policy pursued by Byzantium to solidify its control over the area, a policy that was absent in Seljuk governance.