The Battle of Manzikert was fought on August 26, 1071 between the Byzantine Empire and the Great Seljuk Empire for control of Anatolia. As the commercial center for the Byzantine Imperial city, Anatolia was a great loss to the Byzantine Empire and to Christendom.
Because of his military prowess, Alp Arslan, the Turkish sultan of the Seljuk Empire, managed to defeat the Byzantine Emperor, Romanus IV Diogenes, and annex Anatolia. The fiery Turkish sultan had previously laid waste to Byzantine cities in Armenia and Asia Minor. To avoid war, Romanus had even offered to give up Hierapolis if Arslan would give up his siege of Edessa. As expected by Romanus, Arslan refused such terms. Romanus was a bold general but careless in his lack of attention to crucial details. For example, Alp Arslan's spies kept speed with Byzantine troop movements, but Romanus seemed not to be aware that Arslan had more than 30, 000 troops waiting in the wings for his Byzantine army.
Romanus also had to dismiss both his German and Turkish mercenaries for various infractions. He wrongly calculated that the Manzikert victory would fall to the Byzantines; to make matters worse, his insistence for a long, fancy baggage train thoroughly frustrated his troops. In the end, Romanus' heavy cavalry proved no match for Arslan's incomparably swift, light cavalry. The Turks were a formidable enemy, well-versed in the art of guerrilla warfare. When attacked beyond their power to stand their ground, the Seljuks always withdrew. Biding their time, they would wait for confusion and chaos to reign in the Byzantine camp before launching furious attacks against their Christian enemies.
Romanus and his generals lost the war and the Byzantine hold on Anatolia; although Arslan was merciful in his treatment of the Byzantine Emperor, Romanus' own troops were not so forgiving. Romanus died after enduring horrific tortures. Historians will always view the Battle of Manzikert as a significant moment when the Byzantine Empire's exposed vulnerabilities left it open to subsequent Turkish dominion. The victory at Manzikert showed the Seljuks that the Byzantine Empire was not invincible; indeed, many historians link this battle to the beginning of the decline of the Byzantine Empire.
The loss at the Battle of Manzikert may have also led to the Crusades, as all evidence point to the Byzantine Empire's inability to protect Christian pilgrims in the Middle East. The events at Manzikert also ushered in a new era of Islamic dominance in the Turkish region and the decline of Christian Orthodoxy in Asia Minor.