In every meaningful way, the Byzantine Empire and the Islamic Empire were fundamentally different. On the most surface level, there is the obvious distinction between the dominant religions of the two groups. The Byzantines were Christian and the Islamic empires, whether the Umayyads, Abbasids, or Ottomans, were of course Muslim. Conflicts over land rights and other issues kept the two groups in opposition for many years. However, despite the conflicts, Byzantine and Islamic empires not only had similar cultural moments but also were viewed in similar ways by the people of Western Europe, who saw them both as outsiders.
The population 2000 years ago was between 175m to 300m. the estimates vary because of the methods of estimation used by various demographics. the America was populated by the native Indians people at this time.
