The countries of North Africa share a common ethnic, cultural and linguistic identity that is unique to this region. The original inhabitants of North Africa are the Berbers and the Egyptians. Between the A.D. 600s and 1000s, Arabs from the Middle East swept across the region in a wave of Muslim conquest. These peoples, physically quite similar, formed a single population in many areas, as Berbers and Egyptians merged into Arab society. This process of Arabization and Islamization has defined the cultural landscape of North Africa ever since.
The distinction between North Africa and Sub-Saharan Africa is historically and ecologically significant because of the effective barrier created by the Sahara Desert for much of modern history. The Sahara is the dominant feature of the North African landscape, and stretches across the southern part of the region. The Sahara serves as a geographical boundary between North Africa and sub-Saharan Africa and marks a transition zone from the largely Arab population of North Africa to black Africa of the south. From 3500 BC, following the abrupt desertification of the Sahara due to gradual changes in the Earth's orbit, this barrier has culturally separated the North from the rest of the continent. The overwhelming majority of the North African population is concentrated along the Mediterranean and Atlantic coastlines and the Nile river, while the Sahara desert is one of the most sparsely populated places on Earth.
The Sahara desert has therefore played an important role in the history of North Africa. As the seafaring civilizations of the Phoenicians, Greeks, Romans, Arabs and others facilitated communication and migration across the Mediterranean Sea, the cultures of North Africa became much more closely tied to Southwestern Asia and Europe than Sub-Saharan Africa. The Islamic influence in the area is also significant, and North Africa is a major part of the Muslim world.
North Africa has three main geographic features: the Sahara desert in the south, the Atlas Mountains in the west, and the Nile River and delta in the east. The Atlas Mountains extend across much of northern AlgeriaMorocco and Tunisia. These mountains are part of the fold mountain system that also runs through much of Southern Europe. They recede to the south and east, becoming a steppe landscape before meeting the Sahara desert, which covers more than 75 percent of the region. The tallest peaks are in the High Atlas range in south-central Morocco, which has many snowcapped peaks.