This chapter further explores the relationship between knowledge, archives, and power, picking up when the monarch established Madrid as the capital in 1561. This enabled ministers to establish the first European rational factual archives to exercise dominion over overseas domains. My main argument is that the Council of the Indies and, starting in the 1580s, the special imperial boards managed to create three improved spheres of imperial administration thanks to these pioneering factual archives, in the areas of war, finance, and Franciscan affairs. I analyse how royal ministers largely succeeded in implementing various decision-making innovations: understanding the Indies in a synoptic way, improving the allocation of scarce financial and military resources, and identifying dubious requests coming from the New World. In addition, I underline how already in the 1590s this limited but important archival revolution had unexpected social and epistemological consequences within the administrative field. There was the expansion of the power of the secretaries, notaries, and other subordinates whose work and archival expertise allowed the ministers to successfully if selectively improve their most important decisions. This chapter also underscores the important role of secretaries’ wives as archival custodians.