Arab Trick Makers, Saudi Arabia

Versteegh (1997) is uncertain whether to ascribe this distinction to the memory of a real difference of origin of the two groups, but it is certain that the difference was strongly felt in early Islamic times. Even in Islamic Spain there was enmity between the Qays of the northern and the Kalb of the southern group. The so-called Sabaean or Himyarite language described by Abū Muhammad al-Hasan al-Hamdānī (died 946) appears to be a special case of language contact between the two groups, an originally north Arabic dialect spoken in the south, and influenced by Old South Arabian.
During the Muslim conquests of the 7th and 8th centuries, the Arabs forged an Arab Empire (under the Rashidun and Umayyads, and later the Abbasids) whose borders touched southern France in the west, China in the east, Asia Minor in the north, and the Sudan in the south. This was one of the largest land empires in history. In much of this area, the Arabs spread Islam and the Arabic culture, Science, and Language (the language of the Qur'an) through conversion and cultural assimilation.
Two references valuable for understanding the political significance of Arab identity: Michael C. Hudson, Arab Politics: The Search for Legitimacy (Yale University Press, 1977), especially Chs. 2 and 3; and Michael N. Barnett, Dialogues in Arab Politics: Negotiations in Regional Order (Columbia University Press, 1998).