It's because the Umayyads had Damascus as their capital and when the Abbasids took power they moved the capital from Damascus to Baghdad. But since you're asking about the Umayyads, Damascus was different compared to other Western European cities. From Damascus, the Ummayyads could rule their entire empire. They could do this because they had emirs (which are basically govenors) who were appointed to different provinces throughout the empire (they were appointed by the caliphs) and the emirs with the help of local clan leaders in each province governed their appointed province. This really helped the Umayyads because they could rule all the way from Damascus. Everywhere you go has so many states. For example in the United States. And obviously their president is unable to govern all the st