What occurred in the Roman Empire ?

The Roman Empire, at its height (c. 117 CE), was the most extensive political and social structure in western civilization. By 285 CE the empire had grown too vast to be ruled from the central government at Rome and so was divided by Emperor Diocletian (r. 284-305 CE) into a Western and an Eastern Empire. The Roman Empire began when Augustus Caesar (r. 27 BCE-14 CE) became the first emperor of Rome and ended, in the west, when the last Roman emperor, Romulus Augustulus (r. 475-476 CE), was deposed by the Germanic King Odoacer (r. 476-493 CE). In the east, it continued as the Byzantine Empire until the death of Constantine XI (r. 1449-1453 CE) and the fall of Constantinople to the Ottoman Turks in 1453 CE. The influence of the Roman Empire on western civilization was profound in its lasting contributions to virtually every aspect of western culture.

the arab empire adopted the muslim religion as their main belief. arabs would influence the people from the territories they invaded towards islam (the muslim belief).

nevertheless, throughout the history of the arab empire, rulers brought intellectual individuals from other religions to their centers of learning. these other foreigners included jews, christians, greeks, persians, and indians.   these resulted in the adoption of important knowledge developed by these cultures by the arabic empire. for example, the works of aristotle were translated from greek to arab and indian scientists brought the numerical concept of "zero" to the arabs.

nowadays, 93% of the arab population is muslim, which at the same time is subdivided in sects including the sunni, zaini, alawi, shia. the remaining 7% is composed mainly of christians.