How were caliphate a during the Islamic golden age similar to Western European kingdoms following the fall of rome?

During the Islamic Golden Age, caliphates flourished as centers of learning, culture, and trade, much like Western European kingdoms that emerged after the fall of Rome. Both systems promoted the consolidation of power through territorial expansion and governance, fostering advancements in science, philosophy, and the arts. Additionally, each established a network of educational institutions and cultural exchanges that facilitated knowledge dissemination and innovation. However, while caliphates emphasized religious unity under Islam, Western kingdoms often fragmented into feudal systems with diverse local allegiances.