Between 1569 and 1581 Viceroy Francisco de Toledo carried out the largest programme of compulsory resettlement in the colonial Americas, uprooting the dispersed Andean settlement pattern and concentrating the rural population into new grid-plan towns, the reducciones, where tribute could be assessed, doctrine taught and labour drafted. In parallel he adapted the Inca institution of the mita into a rotating conscription that sent roughly 13,500 men a year, with their households, from sixteen provinces to the silver mines of Potosí and the mercury mine at Huancavelica. Conditions in the mines and refineries were lethal, though no reliable mortality series exists; the surviving records show sustained flight from mita provinces, the growth of a class of permanent migrants who had abandoned their home communities to escape the draft, and the passage of vacated community land into Spanish hands. Colonial administrators themselves recorded that the reducciones did not hold: by the end of the sixteenth century officials complained that taxpaying Indians were fleeing in growing numbers. Modern economic research has traced measurable long-run disadvantage in districts that were subject to the mita compared with adjacent districts that were not.
Viceroy Francisco de Toledo forcibly regrouped the Andean rural population into planned towns and instituted a rotating forced-labour draft to supply the silver mines of Potosí
Toledo's visita general, the first systematic count of the Andes, enumerated roughly 1.3-1.5 million tributary Indians and their dependants across the viceroyalty; the sixteen highland provinces made liable for the Potosí mita held on the order of a million of them. The pre-conquest Andean population was far larger, with estimates from about 4 to 12 million, so this baseline is already a post-collapse figure.
No defensible death toll exists. Mortality at Potosí and Huancavelica was notoriously high — mercury poisoning at Huancavelica, cave-ins, silicosis and cold at Potosí — and colonial critics from the seventeenth century onward wrote of millions dead, but those numbers are polemical and no record permits a count of mita deaths as against deaths from the epidemics that struck the same populations.
The compulsory labour draft, the burning or abandonment of old settlements to prevent return, and the campaigns to extirpate Andean shrines that accompanied resettlement are documented in Toledo's own ordinances and inspection records and analysed in the University of Pennsylvania project and in Mumford's study.
Bolivia, Peru