In this research, the effects of the Turks on the Abbasid caliphate during the Samarra period are studied from a methodological point of view and depending on the main Islamic historical sources. The narrations highlight the role of the Turks in the success of the Abbasid revolutionary movement, their military ac- tivities in the administrative mechanism with the establishment of the new state, their contribution to the caliphate of al-Ma’mun and their success in the rebellion movements under the command of al-Mu’tasim in this period. However, they were transferred to the city of Samarra, which was built for them in 222/836, due to their undisciplined behaviour in Baghdad, which was the result of their huge power they derived through their influence on al-Mu’tasim who owed his caliphate to the Turks. In this period, known as the Turkish era or the Samarra period, their influ- ence on the caliphs began to be felt closely in the political, administrative, military, economic and social fields. After their role in al-Mutawakkil’s ascending to the caliphate, they became strong enough to kill the Caliph. After this incident, they became very influential on the administration because they appointed whoever they wanted to the caliphate, and they either deposed the caliphs from the calipha- te or killed them. However, the death of many Turkish commanders and soldiers during the suppression of the Zanj rebellion and the struggle with the Saffarids and the Byzantine campaigns under the caliph al-Muʿtamid ʿalā ’llāh broke their inf- luence on the caliphate. By taking advantage of this situation, the study concludes, al-Muʿtamid ʿalā ’llāh moved the capital back to Baghdad in 277/890 and ended the Samarra period.