ABSTRACT
Relevant sources could also be categorized according to formal criteria: they generally were either written or artistic. Consulting primary sources included elaborate and time-consuming archive work primarily conducted on site in the Vatican and Rome. Secondary sources were incorporated into the analysis wherever relevant. The sources were mostly written in the language of the Church, Latin or sixteenth-century Italian, sometimes also in a mixture of both and/or different local Italian vernaculars. Additional written sources are texts (treatises, manuscripts and folios) produced either during the period of investigation or shortly thereafter focusing on artistic patronage conducted by the popes. Secondary written sources are all written sources used in this book that were not produced during the targeted time (1545–1605), but at a later stage.
