How was Spain able to govern its enormous colonial territories? In 1573 the king decreed that his councilors should acquire "complete knowledge" about the empire they were running from out of Madrid, and he initiated an impressive program for the systematic collection of empirical knowledge. Brendecke shows why this knowledge was created in the first place - but then hardly used. And he looks into the question of what political effects such a policy of knowledge had for Spain's colonial rule.