Decline of the Seljuks
The Seljuk Empire in Persia was at its peak during the reign of Alp Arsalan and his son Malik Shah. With the death of Malik Shah, began the decline of this great empire. The borders of the Seljuk Sultanate were under constant pressure from the Crusaders in the west, the Arabs in the south and the Mongols in the east. A quarrelling and faction-ridden Seljuk dynasty was unable to withstand the onslaught and by 1192, it ended in obscurity.
Once the decline of the great Seljuks began, the lesser Seljuk clans established their own principalities throughout Anatolia. But on June 26th, 1243, the Seljuk army was defeated at Kose Dagi, outside the city of Siva by the Mongol descendants of Cengiz Khan. Subsequently, the remaining Turkish clans were reduced to the role of vassals. The Mongols however, withdrew just as suddenly as they came leaving behind many small states led by obscure chieftains. One among them - Osman was to later found an extensive empire that came to be known as the Ottoman Empire.