Final answer:
The disintegration of the Abbasid Caliphate led to fragmentation of the Islamic world with the emergence of independent dynasties and rival caliphates. This weakened central authority and made the Islamic world vulnerable to invasions. It marked the end of a united Arab-Muslim empire.
Step-by-step explanation:
The disintegration of the Abbasid Caliphate led to a fragmentation of the Islamic world, with the emergence of semi-autonomous dynasties and rival caliphates in different regions. This political devolution resulted in a weakened central authority and allowed for the establishment of independent Islamic kingdoms and states. It also made the Islamic world vulnerable to invasions, such as the Crusades by European Christians and the Mongol invasion. The disintegration of the Abbasid Caliphate marked the end of a united Arab-Muslim empire.