ABSTRACT
Kayı tribe of Oghuz settled into Ahlât after coming to Anatolia. Then they came to Pasinler plain near Erzurum. While Ertuğrul’s two older brothers and co-relatives returning to Ahlât, Ertuğrul stayed here for a while with four hundreds tent people under the command of his brother Dündar but upon the invasions of the Mongols to these places they migrated to Central Anatolia and settled on the sides of Karacadağ by entering the patronage of Seljuk Sultan Alaeddin Keykubad (1219-1236). After the their successful supports to the Seljuk army during the wars of the Seljuks with the Mongols and Byzantine in the time of sultan of Seljuk Keykubad I, at first Karacadağ near the Ankara and then around of Eskişehir were given to them as homeland. Thus, Kayıs who were under the protection of Ertuğrul Ghazi, became a frontiersmanship of the Seljuks on the Byzantine border in Western Anatolia.
When sultan of Seljuk Gıyaseddin Keyhüsrev III (1264-1283) came to frontier of Byzantium after the Cimri event, there was Ertuğrul Bey who was origin of Kayı tribe also among the ones met him. During this welcome Ertuğrul Bey presented some gifts to Gıyaseddin Keyhüsrev III. as a demonstration of his loyalty to the sultan of Seljuk, he gave the young son of his son Osman Bey to the service of the Sultan. Gıyaseddin Keyhüsrev also responded with a gesture to this loyalty of Ertuğrul Bey. He sent Ertuğrul Bey’s grandson who given him as hostage to the Kahta and gave him Pağnik district (nahiye) of the Kahta as iqta. Thus, the progeny of Ertuğrul Gazi continued for a long time in the Kahta. When Yıldırım Bayezid added Malatya to the Ottoman lands in 1399, he left Kahta in the possession of Halil, Bayat and Ahmet who came from the progeny of Ertuğrul Bey. From that date, It is understood that descendants of Ertuğrul Bey continued to keep their life by saving the Pağnik district of Kahta.