Swahili language
The exact number of Swahili speakers, be it native or second-language speakers, is unknown and a matter of debate. Various estimates have been put forward and they vary widely, from 50 million to over 100 million. Swahili serves as a national language of four nations: Tanzania, Kenya, Uganda, and the DRC. Shikomor, the official language in Comoros and also spoken in Mayotte (), is related to Swahili. Swahili is also one of the working languages of the African Union and officially recognised as a lingua franca of the East African Community. South Africa legalized the teaching of Swahili in South African schools as an optional subject beginning in 2020.
Swahili people
There are two main theories about the origins of the Shirazi subgroup of the Swahili people. One thesis based on oral tradition states that immigrants from the Shiraz region in southwestern Iran directly settled various mainland ports and islands on the eastern Africa seaboard beginning in the tenth century. By the time of the Persian settlement in the area, the earlier occupants had been displaced by incoming Bantu and Nilotic populations. More people from different parts of the Persian Gulf also continued to migrate to the Swahili coast over several centuries thereafter, and these formed the modern Shirazi. The second theory on Shirazi origins also posits that they came from Persia, but first settled in the Horn of Africa. In the twelfth century, as the gold trade with the distant entrepot of Sofala on the Mozambique seaboard grew, the settlers are then said to moved southwards to various coastal towns in Kenya, Tanzania, northern Mozambique and the Indian Ocean islands. By 1200 AD, they had established local sultanates and mercantile networks on the islands of Kilwa, Mafia and Comoros along the Swahili coast, and in northwestern Madagascar.