The Abbasid caliphate witnessed the Arab and Persian synthesis as Islam merged with Persian traditions and cultural practices . Unlike the Arab culture, Persian culture was a sedentary culture that emphasized agriculture and urbanization of society. Ancient Persian traditions contributed to the development of an empire and the key features that constitute an empire such as bureaucracy, administration and imperial ideologies as well as a court culture due to its sedentary traditions. Moreover the bureaucracy was virtually exclusively dominated by Persians. Due to the Persian culture, Arabic remained the language of religion, law and natural sciences but Persian became the language of high culture; it was used for literary expression, administration and scholarship. Furthermore, mysticism was introduced to the Islamic civilization. As a result, new ideologies, such as the veneration of the imams was incorporated into Islam and 12er Shi’ism was the state religion under the Safavids. In addition to that, the notion of priesthood developed in Iran, the Ayatollahs , based on Zoroastrian priests. Ancient Persian culture also influenced literature because writers blended mystical themes in their works and wisdom and philosophical literature became prominent. Furthermore the influence on art resulted in more paintings being produced and miniatures in books . When the caliphate became more symbolic and lost its political power and control , Turkic groups, such as nomads and slave soldiers from within the administration, seized the opportunity to invade, control and influence Islamic civilization.
The Turkic cultural group had a significant impact on the formation of Islamic civilization because they facilitated the expansion of Islamic civilization into new lands. This occurred due to the military efforts by invasion and migration of nomadic pastoral groups, and rise in power of the slave soldiers . When the caliphate disintegrated into a solely symbolic institution, the Turkic slave soldiers became the foundation of military rule in the Islamic world . Turkic slaves were purchased at a young age, converted, educated and trained to work for their masters. They eventually became an elite and extremely powerful group of soldiers who politically dominated the medieval Islamic world such as the Ghulams who made and unmade four caliphs and the Mamluks who fought and won against the Crusaders and Mongols.
Similarly Turks who invaded and migrated to the Islamic world helped spread Islam to new lands due to their lifestyle. Initially the Turks were nomads with a tribal and clan structure and consequently they became excellent horseman, cavalry archers and soldiers. They valued family confederations, were extremely loyal to their clan leaders and their leadership was based on charisma rather than kinship. The women in their society had more power and influence as they participated in commercial activities such as processing raw materials and they had a symbiotic relationship with the sedentary people . When the Turks started invading and migrating to the Islamic world, they changed the course of Islamic civilization. For example the Seljuks invaded Iraq and Iran, permanently weakened the Byzantine empire, and captured Anatolia from where the Ottoman empire emerged and penetrated into Europe . When the Mongols adopted Islam, they extended the influence of Islam to other nomads of central Asia and eastern Europe. The impact of the invasions was initially extremely destructive. For example Baghdad was a cultural metropolis but was reduced to an impoverished province. After destroying the landscape, the nomads introduced their own tribes to repopulate the lands. This resulted in an ethnic change of population and modified the use of the conquered regions such as less cultivation and more herding . Arabic and Persian influence in the lands they conquered lead to the development of new sophisticated literary languages called Ottoman Turkish and Chaghatay.