Northern Africa
Arabic is the sixth most used language in the world with origins in Saudi Arabia in the times even before Islam. It is spoken by over 200 million people worldwide, with a large number of those residing in Northern Africa. The language belongs to the Semitic language family that also includes Hebrew, Maltese, and Tigre just to name a few. Modern Arabic is really two languages if you analyze it; the modern standard arabic and the colloquial arabic. The difference between the two is fairly simple; the colloquial language is used when talking and in informal situations and the modern standard is used when a more formal situation calls for it. Just as any other language there are slight variations depending on the region, (just as the eastern United States uses some different terms than the western half), but overall the modern standard arabic is universal and understood by all arabic speakers.
Arabic letters. Another interesting thing about the language is that unlike English which is read from left to right, Arabic is read from right to left.
The language came to the area through the Quran, which was written in the classical arabic language. The Quran is the basic religious text of Islam and while the language was obviously alive before the printing of the text, (otherwise no one would be able to read it and it would present a host of other logistical issues), the Quran spread the language very effectively. Just like colonization affected the region I classified as Northwestern Africa, religion affected the region and languages of North Africa.
Arabic history sources: http://www.appliedlanguage.com/translation/arabic_translation/arabic_language_history.aspx
http://linguistics.byu.edu/classes/ling450ch/reports/arabic.html



