is widely accepted and increasingly they are also believed to have had the potential to have undergone an urban transformation.

Archaeology on the East African coast from the 1950s through the 1970s was concerned mainly with visible architectural remains. The tombs, temples, and palaces of the Swahili coast were located stratigraphically through archaeological excavation, chronologically by using imported ceramics, and architecturally in relation to better known building styles from the Middle East and India. These often very impressive scholarly efforts were strongly influenced by colonial ideology, which tended toward invasionist interpretations based on ethnic definitions expressed in terms of “Africans,” “Arabs,” or “Austronesians” and often underestimated the creativity of the indigenous peoples of the coast. The limited excavations on the Kenyan coast of stone buildings of “the Arab city of Gedi” and Ungwana (Kirkman 1954, 1966) were superseded by investigations of the Portuguese Fort Jesus in Mombasa (Kirkman 1974) and extensive excavations of the mosque and palace complexes at the major urban site of Kilwa on the southern Tanzanian coast (Chittick 1974).

In the 1980s, extensive archaeological excavations by Chittick (1984) at Manda in the Lamu archipelago off the east coast of Kenya were followed by excavations at Takwa, a site off the coast in an archipelago (Wilson 1980; Wilson and Omar 1996, 1997). Detailed stratigraphic excavations by M. Horton (1996) at Shanga in the same archipelago provided fine resolution chronological sequences and spatial layout of mosque construction and house forms. G. Abungu (1989), working at Ungwana, extended previous work by J.S. Kirkman (1966) and followed the settlement pattern inland up the river Tana. Work at Pate (located again in the same archipelago) by T. Wilson and A.L. Omar (1996, 1997) produced new insights into urban structure.

On the southern Kenyan coast, work by Wilding and later by C. Kusimba (1996) at Mtwapa was carried out in conjunction with investigations at Mombasa. First steps to investigate the role of symbolic values in shaping architectural features, especially Swahili houses, were implemented by L.W. Donelly (1982) on the Kenyan coast. This cognitive approach was extended to the settlement level by S. Kus (1982) in highland Madagascar.

The central coast of Tanzania has been the focus of numerous recent excavations, notably those by Felix Chami of the University of Dar es Salaam, which have transformed our view of the first millennium a.d. chronology and external trading contacts of the early farming communities of this area (Chami 1994, 1998). On Zanzibar and Pemba, a series of surveys focused on stone-built sites have been carried out and followed by excavations (e.g., Clark and Horton 1985; Juma 1996; La Violette and Fleisher 1995). Recent excavations at Unguja Ukuu on Zanzibar have demonstrated trading contact with Roman Egypt as early as the mid-fifth century a.d. (Horton 1996; Juma 1996).

By the eleventh century, the Swahili settlements extended more than 3,000 kilometers along the coastal strip from Somalia to Mozambique, and more than 400 sites were occupied before the sixteenth century (Horton 1987). The settlement system also encompassed the Comoros and the northwestern coast of Madagascar (Vérin 1986, Wright 1984), which were important foci of East African urban development from at least the ninth century a.d. on. The subsistence economy was based on hunting, fishing, cultivation, and livestock and included pottery and ironworking. Trade commodities included slaves, ivory, salt, rock crystal, animal skins, and cloth as well as iron and also gold from the south.

The earliest architectural evidence for the adoption of Islam from the latter first millennium a.d. comes from Shanga in the Lamu archipelago (Horton 1996) and early mosque construction at Sima in the Comorian archipelago. The 1100s and 1200s a.d. saw the widespread adoption of Islam, and this period is marked by a marked increase in settlement area (Wright 1993).

The Offshore Islands

On the Comoro Islands, small fishing and farming communities were established in the late first millennium a.d. (Allibert, Argant, and Argant