o the emergence of urban trade communities, which later became
centers of development of the Swahili civilization. The Swahili lan-
guage, which became lingua franca and an important element of the
nation-building process in modern Tanzania, formed on the basis of
the Bantu languages with a great number of borrowed words from
Arabic, including the most frequently used.
The next wave of migrants, according to Kilwa Chronicle, took
place in the 10th Century. According to a legend, in 957CE, the Per-
sian merchant Ali ibn al-Hassan came from Shiraz with his six sons,
and each of them owned a ship. They became the founders of several
settlements, including Mombasa and Kilwa; after several centuries, all
of them became major trading cities (Nurse and Spear 1985; Ko-
bishchanov 1987). Kilwa soon became the largest center of Islamic
culture on the East African coast. This legend played a significant role
in the relations between the Arabs and the indigenous non-Arab Islam-
ized population (Shirazi), as it allowed the latter to substantiate their
noble Middle Eastern origin (Nurse, Spear 1985: 70–79; Bakari 2001:
68–71; Nicolini 2004: 61–63; Demintseva 2008: 51–52; Korotayev
and Khaltourina 2008: 10–11). Thus, by the 14th Century there were a
number of independent city-states in the region, ruled by Arab Muslim
dynasties or Shirazi. Moreover, by then a stratum of the Arab-Muslim
population of the Middle Eastern origin emerged in East Africa as a
result of several centuries of migrations.