The extensive survival of late medieval bosses in the roofs of many parish churches in Devon has long been recognised. These carvings escaped the widespread destruction of images during the Reformation through their relative inaccessibility, and yet most have never before been recorded; nor has systematic study been made of their design, their positioning within a sacred space, or the ways in which they may have been viewed and used by a largely illiterate audience. This thesis rectifies this oversight in its detailed documentation and photography of figural roof bosses and contextual information from 121 churches across the county, appended as a gazetteer, and in its thorough analysis, which considers the varied interactions between the people of the parish and their carvings. The thesis reviews the literature on roof bosses in Britain, particularly the work of C.J.P. Cave whose studies have hitherto dominated the field, before considering materiality and method, namely the properties of oak, the dating of the timber, the carvers and the carving process, and the surface finish and visibility of roof bosses. The social, religious, and decorative context is then discussed, especially the role of ecclesiastical authorities in the life of the parish church and its people, and the motivation of patrons, clergy and laity in the decoration of their parish church. An exploration of motifs carved on roof bosses follows, with these motifs linked to other images within the parish church, the cathedral and the wider world, to the words of the sermon and the confessional, and to scriptural texts and popular literature. Medieval understandings of vision are considered, as are the circumstances in which roof bosses may have been seen and used. The thesis argues, in particular, that many bosses may have served as mnemonic devices and aids to prayer in a penitential process which sought to cure the soul of sin. The thesis concludes with case studies of six parish churches from across Devon which confirm that these carvings should be recognised as a significant resource for our understanding of the late medieval parish church and its people in the Diocese of Exeter and beyond.

La tête végétalisée est un témoin privilégié de la culture visuelle des Romains. Innovation de l’époque tardo-républicaine et proto-impériale, elle n’en demeure pas moins l’héritière du traitement formel de figures telles que la Rankenfrau et le Rankengott et d’un symbolisme végétal séculaire. Elle évoque une nature naissante ou renaissante qui ne possède pas encore les frontières du cosmos ordonné, et fonctionne comme une épithète iconographique permettant de mettre en évidence un aspect particulier d’un personnage, tel le dieu Oceanus. L’étude des spécificités culturelles et des traditions iconographiques des différentes régions de l’Empire romain, couplée à la mise en série et à l’analyse contextualisée des documents, permet de mettre en évidence les formes de diffusion, de réception et d’appropriation de ce thème ornemental, de sa naissance à son assimilation par le monde chrétien. A côté de tendances relativement homogènes communes à l’Empire, se dessinent quelques courants particuliers, comme l’enrichissement nord-africain de la forme océanique, le renouveau oriental de la bordure à rinceau peuplé héritée de la tradition picturalisante hellénistique, ou « l’humanisation du végétal » gallo-germanique. Entre traditions et innovations, la tête végétalisée du monde romain développe des spécificités iconographiques pérennes qui lui confèrent une signification inhérente à toute forme d’hybridité végétale, tout en permettant à différentes visions du monde de s’exprimer en elle sans se dissoudre. / The foliate head is a privileged witness of the Roman visual culture. This innovation of the tardorepublican and proto-imperial period is the heiress of the formal processing of figures such as the Rankenfrau and the Rankengott and of a secular vegetal symbolism. It evokes a rising or returning nature which doesn’tpossess the borders of the orderly cosmos, and works as an iconographic attribute which highlights a particular aspect of a character, such as the god Oceanus. The study of the cultural specificities and the iconographic traditions of the various regions of the Roman Empire, combined with the serial approach and the in-contextanalysis of the documents, allows to highlight the various forms of diffusion, reception and appropriation of this decorative theme, from its birth to its assimilation by the Christian world. Next to relatively homogeneous trendscommon to the Empire, some particular tendencies take shape, such as the North African enrichment of the oceanic shape, the oriental revival of the border with peopled scroll inherited from the Hellenistic naturalistic tradition, or the Gallo-Germanic « humanisation of the plant ». Between traditions and innovations, the foliated head of the Roman world develops long-lasting iconographic specificities which confer it a meaning inherent to any shape of foliate hybridity, although it allows various views of the world to be expressed in it without being dissolved.