The Abbasid caliphs expanded the empire?

The Abbasids overthrew the Umayyad dynasty in 750 CE, supporting the mawali, or non-Arab Muslims, by moving the capital to Baghdad in 762 CE.

Explanation:

The Persian bureaucracy slowly replaced the old Arab aristocracy as the Abbasids established the new positions of vizier

the best description of postwar writers might be progressive.

following the war, writers showed a tendency to work on artistic or social matters rather than political themes. while postwar literature may not have been the greatest period of english literature, the themes provided excellent critics a high number of novels. such examples include anthony burgess, anthony powell and frank kermode, all of which can be placed under the progressive view.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).