Both nations are industrious tillers of the soil, skilled in metal-work and in mining operations, being probably the direct descendants of the natives, whose great chief _Monomotapa_, _i.e._ "Lord of the Mines," as I interpret the word[258], ruled over the Manica and surrounding auriferous districts when the Portuguese first reached Sofala early in the sixteenth century. Apparently for political reasons[259] this Monomotapa was later transformed by them from a monarch to a monarchy, the vast empire of Monomotapaland, which was supposed to comprise pretty well everything south of the Zambesi, but, having no existence, has for the last two hundred years eluded the diligent search of historical geographers. But some centuries before the arrival of the Portuguese the Ma-Kalakas with the kindred Ba-Nyai, Ba-Senga and others, may well have been at work in the mines of this auriferous region, in the service of the builders of the Zimbabwe ruins explored and described by the late Theodore Bent[260], and by him and many others attributed to some ancient cultured people of South Arabia. This theory of prehistoric Oriental origin was supported by a calculation of the orientation of the Zimbabwe "temple," by reports of inscriptions and emblems suggesting "Phoenician rites," and by the discovery, during excavation, of foreign objects. Later investigation, however, showed that the orientation was based on inexact measurements; no authentic inscriptions were found either at Zimbabwe or elsewhere in connection with the ruins; none of the objects discovered in the course of the excavations could be recognised as more than a few centuries old, while those that were not demonstrably foreign imports were of African type. In 1905 a scientific exploration of the ruins placed these facts beyond dispute. The medieval objects were found in such positions as to be necessarily contemporaneous with the foundation of the buildings, all of which could be attributed to the same period. Finally it was established that the plan and construction of Zimbabwe instead of being unique, as was formerly supposed, only differed from other Rhodesian ruins in dimensions and extent. The explorers felt confident that the buildings were not earlier than the fourteenth or fifteenth century A.D., and that the builders were the Bantu people, remains of whose stone-faced kraals are found at so many places between the Limpopo and the Zambesi. Their conclusions, however, have not met with universal acceptance[261].