The history of Islam concerns the religion of Islam and its adherents, Muslims. "Muslim" is an Arabic word meaning "one who submits to God". Muslims and their religion have greatly impacted the political, economic, and military history of the Old World, especially the Middle East, where its roots lie. Though it is held by non-Muslims to have originated in Mecca and Medina, Muslims believe that the religion of Islam has been present since the time of the prophet Adam.