By around the 1st millennium ADBantu fishermen established trading towns on what is now called Swahili Coast which between the tenth and twelfth century become Arabized. The Portuguese conquered these trading centers after the discovery of the Cape Road. From the 1700s to the early 1800s, Muslim forces of the Sultanate of Muscat reseized these market towns, especially on the islands of Pemba and Zanzibar. In these territories, Arabs from Oman and Yemen mingled with the local "negro" populations, thereby establishing Afro-Arab communities. The Niger-CongoSwahili language and culture largely evolved through these intermarriages between Arab men and native Bantu women. Afro-Arab communities were similarly founded in the Nile Valley, as Arabs intermarried with indigenous tribes of Sudan. However, many other Afro-Arabs in the Sudans had little biological connection to Arab peoples, but were instead essentially of Nilotic origins, albeit influenced by the old Arabian civilization in language and culture. In the mid-to-late 1800s, Arab traders began to move into the central African interior, in pursuance of the ivory trade. Unlike other cases of racial mixing, Arabs, mainly from the Persian Gulf, generally did not view Afro-Arabs as half-caste; Afro-Arabs instead enjoyed similar statuses in their societies as long as the father was Arab. Thus, after the Zanzibar Revolution of 1964, many of the Afro-Arabs that left Zanzibar and settled in Oman were able to attain high political and diplomatic positions and be accepted as Arabs. Racial assimilation of Afro-Arabs with non-Arab Africans also aided Muslim missionaries in the spread of Islam throughout Africa. However, this is not the case for the Afro-Arabs of North Africa, whereas racial discrimination still plays a major role on segregating Afro-Arabs from mainstream Arab population, as found in Tunisia, Algeria, Libya and Morocco. In the Arab states of the Persian Gulf, descendants of people from the Swahili Coast perform traditional Liwa and Fann At-Tanbura music and dance. The mizmar is also performed by Afro-Arabs in the Tihamah and Hejaz regions of Saudi Arabia. The ancestors of these Africans were originally brought to the Arabian Gulf as slaves. But today they are fully recognised citizens of the Persian Gulf States, despite the fact that they do not have any Arab ancestry. In addition, Stambali of Tunisia and Gnawa music of Morocco are both ritual music and dances, which in part trace their origins to West African musical styles.
