The Battle of Manzikert (Malazgirt) took place on August 26, 1071 between Alp Arslan, the ruler of the Great Seljuk Empire, and Romanos Diogenes IV, the ruler of the Byzantine Empire, on the plains of Manzikert. The Seljuk army had approximately 50/65 thousand soldiers, compared to an estimated 150/200 thousand soldiers of the Byzantine army. The battle, which lasted until late hours of the same day, ended with a Seljuk victory.
The Macedonian dynasty, referred to as the "Second Golden Age" in the history of the Byzantine Empire, made Byzantium the first-class state of the era in the 10th century. During this period, the Muslim raids into Anatolia were stopped, Byzantium occasionally threatened the Islamic world, and Northern Syria changed hands. Similarly, Byzantium maintained its superiority in the Balkans and Italy. However, in the 11th century, the golden ages of Byzantium ended with the death of Basil II, the famous emperor of the Macedonian dynasty, in 1025. The measures taken against the rebellions in the Balkans and the Turkish raids threatening the lands in the East were inadequate, and thus Byzantium entered a period of failure both internally and externally.
The famous commander of Cappadocia, Romanos Diogenes IV, married the widow of the deceased Emperor Constantine X, Empress Eudoxia, in 1067 and ascended to the throne. However, there were many problems waiting for the new emperor; internal rebellions, new enemies emerging on the borders, an army plundering its own lands because its salaries were not paid, etc. Wanting to stop the enemy advance in the East, Emperor Diogenes left Constantinople and went to Anatolia, and began to prepare for war against the Seljuks. The Seljuk Sultan Alp Arslan, on the other hand, heard that the Byzantine army was approaching when he set out from Syria to conquer Egypt and thus returned to Ahlat, setting up his headquarters in the Rahve plain near Malazgirt.
In this open field battle that continued from noon until night on August 26th, the Byzantines suffered a heavy defeat. Next day, the Byzantine army was completely destroyed, and the rest were captured. Although the emperor fought very well, he was injured and was captured, and was brought before Alp Arslan along with many captured commanders. According to the peace treaty signed between the parties:
- The Emperor will pay 1.5 million gold coins hor his liberation
- The Byzantine State will pay 360,000 gold coin as taxes to the Seljuks every year
- All Muslim prisoners held by Byzantium will be released
- The Byzantines will provide military assistance to the Seljuks when necessary
- The emperor will marry one of his daughters to the sultan's son
- Antakya, Urfa, Menbic and Malazgirt will be left to the Seljuks
After the peace treaty was signed, Alp Arslan allowed Diogenes to return to Istanbul unharmed. However, when the Byzantine Senate received news of the defeat, it dethroned Romanos Diogenes IV and declared Mikhail Dukas VII as emperor in his place. Diogenes was imprisoned in Kutahya, and died in the dungeons of Kinaliada island the following year.
At the end of the Battle of Manzikert, the Byzantine Empire, the heir of Rome in the East, the greatest empire of the ancient era that had ruled over the continents of Europe, Asia and Africa since the 4th century BC, entered a period of collapse. The battle also played an important role in the change of the cultural and ethnic structure of Anatolia. After the victory, the gates of Anatolia were completely opened to the Turks. Since the Byzantine army was dispersed, in the following years the Turks entered the interior of Anatolia without encountering any significant resistance and advanced to the shores of the Aegean and Marmara sea in a short time, and established the Saltuklu, Mengucuklu, Danismendli, Dilmaçogullari, Ahlatsahlar, Yinalogullari, Çubukogullari and Artuklu states on these lands. The West saw the Turks as a threat and decided to expel them from Anatolia. In fact, the European catholic church launched the Crusades against the Turks in 1095.