Almost half the Indian inhabitants of Peru, some 600 thousand, lived in the southern highlands in 1570. Many large repartimientos dotted the landscape: About 142 of the 260 holdings of the south sierra had more than a thousand residents. The largest population unit in all Peru, the Crown repartimiento of Chucuito, was composed of almost 75 thousand people at the time of Viceroy Toledo's visita general. Further, the rate of population change for the region was the lowest of all Peru from the 1570s to 1600s: The tributary population declined at only – 1.1 percent annually, and the total population fell at –1.2 percent each year. Thus, the broad outlines of population change in the southern highlands are clear, but the details of the process are still poorly understood. The region is vast: It is almost a country within a country. Many communities made up each repartimiento; we are dealing with more than a thousand such population clusters. It is impossible to study them individually. Once again, we are forced to select some areas and problems to examine in greater depth. The balance must await the results of the ongoing investigation of other researchers.