The inclusion of Çorum to Anatolian Seljuk State was in the period of Kılıç Arslan I . Çorum Governor Obruna had to ask for help from Kılıç Arslan during the war with Crusaders and it is estimated that the castle was built by Kılıç Arslan I.
The conquest of Çorum by Kılıç Arslan I caused a conflict with Danishmends.
Çorum developed a lot in the period of Anatolian Seljuks after Kılıç Arslan I . It is understood that there were Camii Kebir (The Great Mosque) Pazar Mosque, Abdi bey Mosque, Defterdar Mosque, Burhan Kethüda Mosque and Süleyman Ağa Library in Çorum.
Çorum was changed into Region Command in the period of Gıyasettin Keyhüsrev II. (1237-1245)
In this time, the rebellion by Baba İshak with Turkomans , a dervish , was quelled. Baba İlyas who was the closest follower of Baba İshak came to Çorum after the death of Baba İshak and continued his post. His son Aşık Paşa replaced him later. Then Aşık Paşa’s son Elvan Çelebi continued.
Anatolian Seljuks were defeated in the battle of Kösedağ held between Mongolians and Anatolian Seljuks in 1243. The conflict period in Anatolia began. This affected Çorum, as well. Hüsamettin who had Karahisar Temürli also conquered Çorum and Osmancık in this conflict period. Emir Celalettin, son of Kunduz Bey, defeated Mongolians in 1276 and seized Çorum and Amasya.