Hippolyte Bellangé a connu une longue carrière qui s’est étendue de la Restauration au Second Empire. Après avoir exposé ses premières peintures au Salon de 1822, cet élève de Jean-Antoine Gros s’impose rapidement dans le milieu comme l’un des principaux chantres de la légende napoléonienne. Élevé en pleine gloire et effervescence du 1er Empire, il appartient à une génération d’artistes qui, au lendemain de Waterloo, va transposer dans son œuvre toute une palette de mélancolie et de nostalgie envers cette rutilance passée, tout autant entraperçue que fantasmée. Le succès de Bellangé, fortement corrélé à un contexte propice à la propagation de la légende napoléonienne, donne un aperçu intéressant sur les évolutions de l’opinion publique d’une part, et des attitudes politiques d’autre part, vis-à-vis de la figure de Napoléon Bonaparte. Ses œuvres se caractérisent en outre par l’application qu’il met dans l’évocation et la description du quotidien. Son installation à Rouen lui donne notamment l’occasion de créer une iconographie renouvelée de la campagne normande. Homme public et artiste aux multiples facettes, sa carrière a par ailleurs été marquée par son activité de conservateur du musée des Beaux-arts de Rouen. Ce parcours pluridisciplinaire nous offre un champ d’étude remarquable et une documentation précieuse sur la carrière et le statut des artistes du milieu du XIXe siècle. L’analyse de la vie et de l’œuvre d’Hippolyte Bellangé, resituées dans leur contexte politique, nous offre enfin l’occasion de questionner les notions d’art engagé, d’art populaire et d’art patriote dans les années qui ont suivi le 1er Empire. / Hippolyte Bellangé had a long career that extended from the Restoration to the Second Empire. After exhibiting his first paintings at the Salon of Paris in 1822, this disciple of Jean-Antoine Gros quickly established himself in the artistic environment as one of the main promoters of the Napoleonic legend. Raised during the full glory and effervescence of the First Empire, he belonged to a generation of artists who, the day after Waterloo, transposed into their work a whole palette of melancholy and nostalgia towards that past glow they half-caught a glimpse of, half-fantasized about. Bellangé's success, which was strongly correlated to a context that was supportive to the spread of Napoleonic legend, gives an interesting insight into the evolution of public opinion on the one hand, and political attitudes on the other, towards the figure of Napoleon Bonaparte.His works are also characterized by the application he puts into the evocation and description of everyday life. His moving to Rouen gave him the opportunity to create a renewed iconography of the Norman countryside. Simultaneously a public figure and a multifaceted artist, his career has also been marked by his position as curator of the Musée des Beaux-arts of Rouen. This multidisciplinary background definitely offers a remarkable field of study and a valuable documentation on the careers and the status of artists in the mid-nineteenth century. The analysis of the life and work of Hippolyte Bellangé, reviewed in their political context, finally gives us the opportunity to question the notions of committed art, popular art and patriotic art in the years following the First Empire.

While the role of photography in enforcing hegemonic ideologies has been amply studied, this thesis addresses the under-researched topic of how photography undermined dominant narratives in specific historical circumstances. I argue that, in the later part of the long nineteenth century, photographs were used to represent the natural world in contexts where their functions were uncertain and their capacities not clearly defined, and that these hesitations allowed for the expression of resistances to dominant social attitudes towards nature. I analyse how these divergences were articulated through three independent case studies, each addressing a corpus of photographs which has been marginalised in scholarly discourse. The case studies all concern photographs of vegetation. The first one discusses photographs produced around Fontainebleau during the Second French Empire, commonly understood as auxiliary materials for Barbizon painters, and argues that they were in fact autonomous representations, reflecting marginal modes of experiencing nature which resisted its prevailing construction as spectacle. The second case study examines a photographic series depicting Amazonian vegetation, published between 1900 and 1906, and shows how, in attempting to satisfy conflicting ideological demands, these photographs undermined the hierarchies enforced upon the natural world by colonial science. The third case study analyses photographs from an early twentieth-century environmentalist treatise, and demonstrates how, while the author's discourse seemingly complied with conventional attitudes towards nature, the photographs instituted an ethical stance opposed to early conservation's aesthetic focus and anthropocentrism. Throughout the case studies, I argue that the photographs were consubstantial to the emergence of these resistances; that dissenting representations stemmed from a tension between their producers' lived experience and the ideological frameworks which informed each context; and that this process engendered remarkable formal innovations, which are not usually associated to non-artistic images. I contend that radical renewals of visual expression occur in all representational contexts, as image producers adapt their tools or forge new ones according to circumstances, and that more attention must be paid to such visual innovations outside the field of artistic production.