The main interlacustrine kingdoms have been presented, on the evidence of their royal genealogies recalling up to thirty reigns, as stretching back to a ‘Chwezi’ period some five centuries ago. This view was promoted especially in the Kitara zone, comprising Bunyoro and regions to its south and, as a close linguistic grouping, extending to Nkore, Karagwe and Buhaya. Rwanda to the south-west and Buganda to the east, though each rather distinct, share some of the same cultural and traditional features. In the central Kitara zone it has been further argued that the ‘Chwezi’ period is represented by various impressive archaeological sites – hilltop shrines, notably at Mubende, with special and archaic objects; complex earthwork enclosures at Bigo and elsewhere; and the concentrated settlement nearby at Ntusi. Certain of these have been claimed as Chwezi royal capitals of ancient Kitara, and specific features have been compared with royal abodes of recent centuries. Such literal interpretation, let alone royalist manipulation, of oral traditions is now considered too simplistic; not only are the Chwezi generally regarded as gods or mythical heroes, but also the role of archaeology is now seen as something more positive than the mere verification of verbal evidence.
Renewed archaeological research indicates that Ntusi was occupied from about the eleventh to the fifteenth centuries a.d. and that the earthworks, including Bigo, and the settlement on Mubende hill fall into the latter half of that span. This cultural grouping thrived on a combination of cattle-keeping and grain cultivation, as is especially clear at Ntusi on fertile ground in the midst of the Bwera grasslands. It may have been the growing strains of a delicately balanced economy as competition increased for cattle and the pastures which led to its eventual breakdown. During the last half-millennium Bwera has been a peripheral and lightly populated district between Bunyoro, Nkore and Buganda. It is difficult to imagine these later kingdoms developing directly out of a supposed ‘Chwezi’ one based at Ntusi and the Bigo constructions.
Two periods of marked change are discernible therefore, one around the middle of this millennium, the other at its beginning. That earlier, mid-Iron Age, revolution witnessed the introduction of cattle on a large scale and the first intensive exploitation of the interlacustrine grasslands. Cattle becoming then an economic asset, it may be inferred that ownership of stock and defence of the pastures became sources of prestige and patronage, with obvious social, political and military implications. This situation opened opportunities for other specializations, including the production of salt for distant distribution. Traditions concerning gods and heroes, and the continuing popular chwezi cults, illustrate the changes and may also echo the cultural and economic importance of iron and its working among agricultural populations from before the pastoral revolution.