The aim of this thesis is to identify maritime activity and patterns of spatial organisation through archaeological survey at first millennium coastal settlements in the Zanzibar Archipelago, in order to explore the nature of proto-Swahili harbours and evaluate the role of maritime activity as a component of proto-Swahili settlement in the region. Despite frequent scholarly reference to the maritime cultural identity of the Swahili there has been little consideration of the maritime archaeology of first millennium East African coastal settlements. Although intertidal zones associated with later sites have been surveyed, no investigation has ever been conducted into the nature of proto-Swahili harbours. The work presents an inductive investigation of proto-Swahili harbours between the sixth and eleventh centuries in the Zanzibar Archipelago, based on observations of industrial and maritime activity in open areas along the shorelines of Swahili ports.

This thesis focuses on the geophysical survey, GIS analysis, and evaluation of the maritime areas of three contemporary sites; Unguja Ukuu (c. 600-1100 CE) and Fukuchani (c. 550-800 CE) on Zanzibar, and Tumbe (c. 600-950 CE) on Pemba.

The analysis demonstrates the existence of communal harbourfront activity areas hosting iron-working, crafting, and trade, and a previously unknown shoreline mosque. The comparison of the three sites indicates a pattern of maritime activity and settlement organisation in the Zanzibar Archipelago based on knowledgeable exploitation of the maritime cultural landscape. It is argued that the proto-Swahili coastal settlements of the Zanzibar Archipelago were deliberately located on beaches with shallow, sheltered harbours and convenient land-sea access in order to exploit the near-shore coastscape. Maritime activity therefore appears to have been an important component of proto-Swahili settlement from the earliest phases of permanent occupation, whilst the construction of shoreline mosques in the ninth century reflects the development of a syncretic maritime-Islamic coastal Swahili identity.