The Zenj Empire was established in 980 AD by Ali ibn Hasan of the Shirazi Dynasty. The founding of the empire was also based on a joint venture that entailed Persians and Shabankara Kurds. The Shabankara Persians, specifically, were from the Shiraz region in southern Iran.
The Zanj Empire was the successor state to the Kilwa Empire first built by the Bazrangids. Evidence from East African traditions, chronicles, coins, and architecture indicate that the Barzangids were succeeded by the Shirazi Dynasty. Moreover, statements from a European traveler, Joao de Barros, and reports from Muslim travelers/geographers imply of such a succession happening.
The extent of the Zanj Empire entailed the entire coast of Lamu in the north to Sofala in the south. The empire fell in 1513 AD to the Arabs who came from Oman. Today, citizens of the Zanzibar archipelago and the Swahili (Lindi to Mombasa and Malindi) coast of East Africa call themselves "Shirazi". Even a main political party in Zanzibar was called the "Afro-Shirazi Party". Moreover, the very foundation of the modern town of Zanzibar (the stone town center) was laid during the late reign of Shirazi Dynasty.