The rapid expansion of Islam resulted in an ummah too large to be governed by one polity, as was made clear by the fall of the Abbasids. Over the course of the 10th century, small military states governed by the amirs competed for power in Central Asia while Egypt maintained its own Fatimid Caliphate. Despite this fragmentation, each region of the Islamic world boasted notable cultural achievements during this time period; in Egypt, universities were established, in Persia there was a literary and philosophical boom, and Cordoba also became a cultural capital. Armstrong argues that the disbanding of the Caliphates had allowed Muslims to gain a sense of international connectedness and cultural inventiveness.

Shia discontent with the rise of Sunni politics would result in a violent movement amongst the Shia to assassinate Sunni leaders, but this violence backfired by damaging the reputation of Shia Islam among non-Shias. As a result, Sunni Islam became even more popular amongst everyday people, and philosophers like al-Ghazzali (d.1111) promoted an unpretentious vision of Islamic mysticism. Across all strata of Islamic society, a “religious revolution” was underway.