The Zimbabwe culture of present day Southern Rhodesia and Mozambique, of which the main occupation at the nuclear site of Great Zimbabwe dates from the twelfth to the fifteenth centuries, is best known for its external trade in gold, ivory, and copper and for its monumental stone ruins. But while important in terms of prestige exchanges at the diplomatic level, mining and trade seem to have been seasonal occupations fitted in round the annual cycle of subsistence cultivation dependent upon the rains (Barreto 1667: 489–92; Mudenge 1974; Phimister 1974). Patron–client relations between Shona-speaking groups were expressed by limited, symbolic tribute in agricultural labor, military service, gold, ivory, livestock, wives, slaves, local produce, and other prestige items (Barros 1552:271; Conçeicão 1696: 66; Andrade 1955: 306, 310–11), but until recent times basic control over social and political groupings was probably exercised through belief in various levels of spirit cult, ranging from the grass-roots system of individual guardian spirits (mudzimu, sing.) in the ancestral cult controlled by village elders in the extended family and descent group, through a hierarchy of ritually senior, loosely territorial land spirits (mhondoro) holding sway over the progressively larger land shrine realms (nyika) of neighborhood leaders, petty chieftains, chiefs, and paramounts. Leaders at each level influenced a following of both spirits and living people who were interconnected, and the fluctuating network of alliances that existed between leaders was symbolized and kept going by an intermittent traffic in tribute, diplomatic missions, and religious congregations coming to the shrines and leaders located at the various headquarters (zimbabwes) of the confederacy. When the confederacy was large and free from civil wars and secession, the system sometimes culminated in a unifying central cult devoted to a supreme spirit (such as Mwari Nyadenga, Leza or Mulungu) supporting a Mambo, whom the Portuguese called King or Emperor (Santos 1609: esp. 196–9; Abraham 1966; Bullock 1928; Garbett 1966, 1969; Holleman 1953).