What makes Hospitaller art collecting interesting? This paper sets out to answer the question by showing how art collections, built up over the course of the lives of individual knights of the Order of St John and subsequently dispersed, present an uncommon field of research in the history of art collecting in early modern Europe. 1 Knighthood meant adherence to rules and regulations founded upon the vows of poverty, chastity and obedience. Despite these determining principles, art patronage and collecting were also considered the norm within the life of a young nobleman who took those same vows. The Order’s rules did cause tensions in the acquisition and disposal of works of art, rendering art collections as much a communal matter as a private one, yet Hospitaller collectors succeeded in accumulating magnificent collections within the parameters established by the Order’s regulations.