The purpose of this dissertation is to reconstruct the artistic patronage of Cardinal Alessandro Farnese (1520-89), to examine the mechanisms of that patronage, and in particular the role of intermediaries, and finally to consider what can be known of the Cardinal's personal taste and the extent to which it affected the ultimate appearance of the work of art. The study is based on extensive new archival material, as well as printed sources. In the introduction the Cardinal's biography and the character of his court are outlined, and the nature of the source material is discussed. Chapter 2 is a survey which aims to depict the cultural environment in which Alessandro grew up: the patronage of his grandfather Paul III, and his father Pier Luigi Farnese, and especially the projects in which Alessandro himself was involved are covered. In the following two chapters the history of Alessandro's artistic commissions, secular and religious,is reconstructed, and his development in relation to contemporary events is considered. His commissions for works of decorative art, which follow a rather different pattern, are discussed separately in chapter 5. Chapter 6 examthes the role of the Cardinal's various artistic advisers, such as Paolo Giovio, Annibal Caro, Fulvio Orsini and Onofrio Panvinio the responsibility delegated to them and their influence. In the final chapter I outline my conclusions about Alessandro's intentions as a patron and the nature of his taste. New documentary material is presented in the appendix.