The Andean heartland around Cuzco centered the historic Inca empire. It extended to include Potosí as silver rose to fuel global trades after 1550. The regions remained integrated in Spain’s empire until reformers facing a slow revival of silver in the eighteenth century split them in the 1770s, keeping Cuzco tied to Lima while linking Potosí to Buenos Aires. The great uprisings of the 1780s extended across the new boundary, encompassing the heartland in conflict. When imperial struggles and uncertainties spread after 1808, the powerful hesitated due to fear of new popular risings—until outside armies led by Bolivar in the 1820s forced liberations that led to long debates about whether the heartland should be one nation or two. Trials of union gave way to separation between Peru and Bolivia in the 1840s as both searched for commercial prosperity that might fill empty treasuries.