Alongside the traffic of material goods and the lighter, quasi-immaterial exchange of paper-based value, the exchange of human beings as commodities also left a trail of paperwork and methods that exemplify the extent to which global European economic and financial power was built upon the practice of slavery, from which both private individuals and institutions as well as states made a considerable amount of money. The documents in this section illustrate how this traffic was conducted and regulated, and how human beings were treated like any other sort of merchandise which, for example, could be subject to an insurance policy with detailed contractual conditions (doc. 84). States and empires did not just benefit from slavery by selling licences (asientos) for private individuals, for a fee (docs 86 and 87). Other than cash or credit, some of them also raised taxes in specie, i.e., in human beings who were used as a form of tribute (doc. 85). The dealings registered in these papers demonstrate how slavery was not something separate and conducted on the margins, but a central practice and a source of income perfectly integrated in the different commercial, financial and fiscal mechanisms of European public administration and business, including the use of enslaved individuals as hostages to be exchanged for a ransom (doc. 88), another lucrative aspect of the slave trade in the Mediterranean.