On August 26, 1071, near Manzikert, Armenia, the Seljuks inflicted a decisive defeat on the Byzantine Empire and paved the way for settlement in Anatolia, and the Byzantine emperor Romanus IV Diogenes was captured.
The battle opened the Seljuks' path to the Middle East and the Balkans. The military actions predetermined the future of the region for centuries.
The Seljuks formed a huge crescent, using archers and flank raids to harass the advancing Romans. The Byzantine infantry managed to capture the enemy camp, but the Seljuks withdrew their cavalry and, using archers, continued to weaken their opponents' wings on the principle of "hit and run", while at the same time the "horns" of the crescent began to close in on the Byzantine rear. Placed in this awkward position, Roman ordered a retreat to Manzikert.
The Turks took advantage of the confusion and the falling darkness and attacked the scattered Byzantine army. The wings were swept away, and the center was surrounded and defeated. Roman IV was captured, and his Varangian guards - killed while defending him.
The clash between the Byzantine Empire and the Seljuks began as early as 1060, when the Turks began their first raids into Armenia. By 1068, the Seljuks had conquered most of this province, along with the major cities of Ani and Caesarea. Constantine IX and Constantine X – both far from the warrior emperors who had led the Roman Reconquista to a defeated end – were unable to counter the increasing Turkish advance. With the accession to the throne of the energetic Romanos IV Diogenes, the Byzantines began a series of steps to regain lost ground in northern Syria and eastern Anatolia. A Byzantine army succeeded in pushing the Turks out of Syria, although it was ultimately defeated after the personal intervention of Sultan Alp Arslan. However, the Seljuk ruler chose to make peace (1069) and turn his attention to the powerful Fatimid Caliphate in Egypt.
Byzantine advances towards the Caucasus led to the Battle of Manzikert. The Seljuk victory led to the construction of the Bachkovo Monastery.