Very detailed video on the Swahili Coast

Sep 2015
Extra info to this very interesting thread:
By 1513, the sultanate was already fragmented into smaller states, many of which became protectorates of the Sultanate of Oman
These quotes are from The Swahili Culture | World Civilization

It is the mixture of Perso-Arab and Bantu cultures in Kilwa that is credited for creating Swahili as a distinctive East African culture and language. Nonetheless, the Muslims of Kilwa (whatever their ethnicity) would often refer to themselves generally as Shirazi or Arabs, and to the unconverted Bantu peoples of the mainland as Zanj or Khaffirs (infidels).
Of course the highlands was never exactly populated (basically) so that should tell us plenty about the latent mind and agenda of the author(s) of this page. Whilst the following is also patently present: many ways an extension of mainland African traditions, although structural elements, such as domes and barrel vaulting, clearly connect to Persian Gulf area and South Asian building traditions as well. Exotic ornament and design elements also connected the architecture of the Swahili coast to other Islamic port cities.
In contrast to past historical accounts this idea of something like representing various groups (sometimes called "schools of thought" in order to resemble legitimation), of an issue/argument, or opposing sides, tends to represents groups with an agenda other than historical inquiry. This last featured in history as represented before the 1960s when relevant, when there was genuine academic dispute.