the Viceroyalty of Peru was not organized until the arrival of a later Viceroy, Francisco de Toledo, in 1569. Toledo ended the indigenous Neo-Inca State in Vilcabamba, executing the Inca Túpac Amaru. He resettled the indigenous people in Spanish-style settlements in a process called reductions, promoted economic development using commercial monopoly and increased the production of the silver mines of Potosí, using an Inca institution of forced labor for mandatory public service called mita. The integration of Spanish culture into Peru was carried out not only by Pizarro and his other captains, but also by the many Spanish who also came to Peru to exploit its riches and inhabit its land. These included many different kinds of immigrants such as Spanish merchants, peasants, artisans, and Spanish women. Another element that the Spanish brought with them were African slaves to work alongside captive Incas for use in labor with things such as agriculture and mining for silver. These people all brought with them their own pieces of Spanish culture to integrate into Peruvian society. Effects of the conquest on the people of Peru The long-term effects of the arrival of the Spanish on the population of South America were catastrophic. While this was the case for every group of Native-Americans invaded by Europeans during this time period, the Incan population suffered an exceptionally dramatic and rapid decline following contact. The population decline for the Inca Empire from 1520 to 1571 is roughly estimated at from 10 to 12 million in 1520 to less than 3 million in 1570 with the population still declining after 1570. The single greatest cause of the decimation of native populations was Old World infectious diseases, carried by colonists and conquistadors. As these were new to the natives, they had no acquired immunity and suffered very high rates of death. More died of disease than any army or armed conflict. As the Inca did not have as strong a writing tradition as the Aztec or Maya, it is difficult for historians to estimate population decline or any events after conquest. But, it is sometimes argued, and equally disputed among scholars that the Inca began to contract these diseases several years before the Spanish appeared in the region, as it was possibly carried to their empire by traders and travelers. The outbreak, argued to be hemorrhagic smallpox, reached the Andes in 1524. While numbers are unavailable, Spanish records