Increasing tax demands led Spanish rulers to expand baronial privileges.

Evidence

When the kingdom passed to the Habsburgs it became increasingly marginalized and the older representative assemblies, the Eletti and the Universita, became little more than the instruments of a feudal aristocracy which was entirely beholden to the crown. As the Spanish empire steadily declined during the late sixteenth and early seventeenth centuries, the Spanish kings demanded more and more in taxes from their subjects. In Naples and Sicily they purchased these by granting the baronry ever increasing power. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 1707