The Baba Ishak rebellion, the largest Turkmen uprising in the history of the Anatolian Seljuk State, started in 1240 is a religious-looking political rebellion which was occurred by that the nomadic Turkmen who were trapped in a narrow area in Anatolia and became impoverished, grouped around Baba Ishak because of some applications in the administration of Gıyaseddin Keyhüsrev II and by the inclusion of Harezm Turks who were exiled to Aleppo and Antep regions into this group and broke out in Adıyaman and Kahta regions and then spreaded to Malatya, Maras, Sivas, Tokat and Amasya. After Gıyaseddin Keyhüsrev II sent troops against Baba Ishak and later Baba Ishak was killed by hanging in Amasya, this rebellious group came to wrangle and threatened the capital city Konya after giving great damage to Amasya city and its people. After Kayseri, the rebels who went to Kırşehir met with the Seljuk army in the Malya Plain near Kırşehir. The Seljuks, including Frank soldiers into their armies, defeated the rebels here and suppressed the rebellion. Despite this suppression, the Anatolian Seljuk State was weakened by military, political and economic reasons, then defeated by the Mongols in the Kösedağ War (1243) and the Anatolian lands gradually entered the Mongol domination. The arrival of Baba Ishak rebellion to Amasya, the hanging of the chief here and the events afterwards are important in terms of the Anatolian Seljuks and Amasya. This subject will be studied in a wide way by taking advantage of the main sources on the period such as Ibn Bibi and later works.