The attention that Enlightenment philosophers and their patrons and readers paid to theories of friendship in the eighteenth century has been examined by cultural historians. Yet, art historical interest in the subject has been limited to the iconography of friendship deployed around 1750 by the marquise de Pompadour, royal mistress of the French king Louis XV, to secure her position after the end of their sexual relationship. Examining the numerous allegories commissioned by elite European patrons before and after Pompadours death, my research challenges the assumption that an iconography of friendship began and ended with the marquise. It identifies the actual and metaphorical settings of Pompadours and other patrons allegories that were located in gardens characterized by their remove from court and city and by the emerging English landscape style, and it contextualizes these sites of friendship within a contemporary critical discourse on the nature and existence of friendship. Enlightenment thinkers, especially the French Voltaire, the marquise de Lambert, and the English Joseph Addison and Alexander Pope debated the nature and existence of friendship in society throughout the eighteenth century. They considered who should be counted as a friend, the extent of friends obligations to each other, the function of friendship, and the possibility of true and perfect friendship. They were informed by philosophers of antiquity, the Renaissance, and the seventeenth century who had written on friendship and who, like their eighteenth-century counterparts, found true friendship to be a rare virtue. The dissertation begins with the contemporary literature on friendship and a re-examination of the marquise de Pompadours friendship iconography, and it concludes with the project initiated by the Russian empress Catherine the Great to memorialize her friend, Voltaire. These two patrons of friendship allegories, like the others discussed here, variously found themselves on the margins of the elite societies to which they desired membership, and they deployed their representations of friendships as claims to such status. Their allegories of friendship commemorated personal relationships, but they were also means by which they claimed to possess the virtue of friendship and to share that virtue with select, influential friends.