Nubians are a Nilo-Saharan speaking ethnic group indigenous to the region which is now northern Sudan and southern Egypt. They originate from the early inhabitants of the central Nile valley, believed to be one of the earliest cradles of civilization. In the southern valley of Egypt, Nubians differ culturally and ethnically from Egyptians, although they intermarried with members of other ethnic groups, especially Arabs. They speak Nubian languages as a mother tongue, part of the Northern Eastern Sudanic languages, and Arabic as a second language.