Since the inception of Renaissance scholarship in the late 1800s, the mendicant orders of friars – above all the Franciscans – have been considered pivotal for the artistic and urban renewal underway in Italy from the 1200s onwards. This dissertation provides the first comprehensive study of the ‘third’ mendicant order: the Hermits of St Augustine, long dismissed as pale imitators of the Franciscans and the Dominicans. My major re-evaluation of the Augustinians’ artistic legacy reveals them to be innovative patrons who used art discerningly to promote a distinctive identity, with much wider implications for our prevailing understanding of Franciscan patronage as a normative model for artistic renewal. My thesis systematically considers the use of different media – illuminated manuscripts, panel paintings, wall paintings, and shrines – both as individual pieces, and combined as part of the church interior. By building on extensive field work, my research brings into conversation a wide array of dispersed artefacts, isolated hermitages, and new archival evidence to investigate the complicated mechanisms behind commissioning art. Scholars have questioned whether Augustinian artistic patronage had any distinctive characteristics at all. My research reveals for the first time the existence of overarching iconographic and artistic themes. In contrast to St Francis for the Friars Minor and St Dominic for the Order of the Preachers, the Augustinian friars lacked a charismatic contemporary saintly founder, and were threatened with suppression on account of their recent foundation. In reaction to this, the Hermits forged an origin myth in which they claimed to be founded directly by the late antique church father St Augustine. I argue that the Augustinians employed art as a key platform to develop this fictive past which proved to be crucial to their survival and emphasized eremitical themes often overlooked by the resolutely urban focus of scholarship on late medieval Italy. This dissertation examines the art, sanctity, and unique identity of the Augustinian friars, and, more broadly, provides a new model for how control over the past can be exercised through artistic patronage and how artworks played a crucial role in the institutional consolidation and survival of a religious order.