 On October 12, 1761 Amat succeeded José Manso de Velasco, 1st Count of Superunda as Viceroy of Peru.He was followed by Manuel de Guirior, Marqués de Guirior on July 17, 1776.In September 1767, he executed the expulsion of the Jesuits missionaries from the Viceroyalty of Peru, following orders from the Crown.