Shirazi era
The "Arab Shirazi era" refers to a period in the history of Southeast Africa (and especially Tanzania), between the 13th century and 15th century, when Persian city-states were founded on the eastern coast of Africa as well as on its islands. These Persian settlers were mostly from the Shiraz region, and the present day Shirazi people claim to descend from these settlers, though this tradition is disputed.
History
Arabs and Persians began trading with Southeast Africa, and building trading settlements on the coast and islands, in the 11th century. Cultural exchanges between these civilizations and the local bantus gave birth to what would develop into the Swahili culture. In the following centuries, commerce from South eastern Africa to the Middle East flourished, and traders coming from Africa with gold and ivory eventually reached as far as India and China. Trading settlements in Southeast Africa grew richer, and between the 13th and 15th century they evolved into city-states, usually governed by sultans. At least 30 such city-states are accounted for. One of the most powerful of them was the Kilwa Sultanate; in his writing, the famous Berber traveller Ibn Battuta mentions Kilwa Kisiwani as one of the richest and most beautiful cities in the world.
The Arab Shirazi Era came to an abrupt end with the advent of the Portuguese at the end of the 15th century. The Portuguese first raided and then conquered the Shirazi/Swahili cities, with the aim of controlling the trading routes in the Indian Ocean. In fact, they did not achieve their aim, as the fall of the Shirazi city-states actually caused trading between Africa and Asia to collapse and eventually extinguish.
Heritage
The Arab Shirazi Era was essentially the beginning of Swahili culture. Later on, this culture would be further influenced by Omani Arabs, that would fight the Portuguese back from Southeast Africa.
One of the most important archeological sites from the Shirazi Era is that of Kaole, north of Dar es Salaam. The remains of the oldest mosque in Southeast Africa can be found there.
Royal House
There is an extant Imperial Persian royal line that retain the title of Wa-Shirazi Sultans including the Sultanate of Hamamvu of the Comoros and the Sultanate of Aldabra (the current incumbent being Hutan Ashrafian).