The correct answer is Kilwa
Around the 8th century, the Swahili people became involved in Indian Ocean trade. As a consequence, they were influenced by Arab, Persian, Indian and Chinese cultures. During the 10th century, several city-states flourished along the coast of Swahili and the adjacent island. They were Muslim, cosmopolitan and politically independent of each other.
Kilwa Sultanate was a medieval sultanate, centered in Kilwa, whose authority, at its peak, extended the entire length of the Swahili Coast. It was founded in the 10th century, and the last native dynasty was overthrown by a Portuguese invasion in 1505. By 1513, the sultanate was already fragmented into smaller states.
Despite its origins as a Persian colony, the extensive marriage and conversion of Bantu locals and subsequent Arab immigration transformed the Kilwa Sultanate into a very diverse state. It is the mixture of Perso-Arab and Bantu cultures in Kilwa, which is credited with creating Swahili as a culture and language distinct from East Africa.
The diverse history of the Swahili Coast has also resulted in multicultural influences on Swahili arts, including furniture and architecture.