In this thesis, the fabrication technology of Roman lead glazes were examined using a number of materials science techniques: namely, electron probe microanalysis, X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy. The overall aim of this work was to discern particular technological styles for a wide group of lead glazes by quantifying the chemical and microstructural features of glaze production. Using experimental replication, it was found that two basic methods of glazing could be identified chemically. When applying PbO alone to an earthenware ceramic, the resulting glaze was in equilibrium with the ceramic as indicated by flat compositional profiles obtained along the glaze cross-section. However, when applying PbO·SiO₂ mixtures to earthenware ceramics, gradient profiles indicative of diffusive mass transfer were obtained from the glaze cross-section. On the basis of these chemical criteria, these two methods of glazing were identified in archaeological material. It has been determined that the earliest lead glazes from Anatolia and Italy (approximately 1^st century B.C.) were made using PbO·SiO₂ mixtures applied to calcareous clays with Fe and Cu oxides added as colourants. Later production (post 2^nd century A.D.), seems to have employed PbO alone applied to non-calcareous clays with no intentionally added colourants. The Roman production of lead glazes was compared to both those of Late Antiquity (4^th – 10^th centuries A.D.) which continued to use PbO applied to non-calcareous clays, and to those of Byzantine and Islamic contexts (8^th – 14^th centuries A.D.) which seem to have used PbO·SiO₂ mixtures applied to both calcareous and non-calcareous clays. It is also argued that the technological features of the Byzantine and Islamic glaze production shared more in common with the contemporary Chinese lead glazing tradition (the Sancai wares of the 7^th century A.D.) which also used PbO·SiO₂ mixtures applied to non-calcareous clays, than with the Late Antique glazing tradition.

L’ensemble constitué par les céramiques en terre cuite à glaçure plombifère, auparavant regroupées sous le terme de « céramiques de Bernard Palissy » puis « suites de Palissy » ou « atelier d’Avon », n’a plus aujourd’hui d’attache géographique concrète ni d’histoire attestée. Il est en effet avéré que la légende et le mythe ont, depuis le début du XIXe siècle, toujours largement dominé. En dépit de leur présence importante au sein des collections publiques françaises et étrangères, la fragilité des connaissances actuelles sur ces pièces rend aujourd’hui leur étude approfondie indispensable. De nature fondamentalement transdisciplinaire, ce travail de thèse explore d’une part leur matérialité, avec la création d’un corpus des œuvres conservées en collections publiques (plats rustiques, pièces de vaisselle moulées, statuettes) et la prise en compte des analyses physico-chimiques ; d’autre part, par un travail minutieux de dépouillement d’archives et de recensement du matériel archéologique, il permet de mieux les situer dans une époque et dans un contexte de production parisien. Ces travaux reviennent ainsi sur l’histoire oubliée de ces objets en enquêtant sur leur origine, leur destination initiale et leur parcours depuis les collections du XVIIe siècle jusqu’aux celles des érudits du XIXe siècle qui les léguèrent en tant qu’objets d’art aux grands musées nationaux. / This PhD thesis studies the whole terracotta lead-glazed ceramics produced in France at the end of the XVIth century and the beginning of the XVIIth century usually attributed to Bernard Palissy himself or his unidentified followers under the name Palissy ware ceramics. Legend and myth are widespread since the beginning of the XIXth century. As a consequence the study of these pieces which have proved to be very numerous in the French and foreign public collections has become essential. This transdisciplinary research examines on the one hand their materiality putting together a body of work (rustique figulines, relief-moulded dishes, statuettes) and taking into account physico-chemical analyses. On the other hand, it helps to place these ceramics in their Parisian historical production context by a meticulous study of archives and archaeological material. The research investigates their origin, their initial destination from the XVIIth century to the collections of French scholars or national museums' collections in the XIXth century.

Cette thèse a pour objectif premier de fournir une documentation complète des différentes céramiques à glaçure plombifère antiques signalées dans les contextes archéologiques de Gaule méridionale et de la vallée du Rhône. L’inventaire a mis en lumière l’existence de six groupes de production de céramiques à glaçure plombifère durant une période comprise entre la fin du Ier s. av. J.-C et le milieu du IIIe siècle apr. J.-C. Ces céramiques proviennent d’Asie Mineure, d’Italie septentrionale, des ateliers de Lyon et de Saint-Romain-en-Gal, du centre de la Gaule, d’Italie centrale et de l’atelier du Capitou (Hérault). Chaque catégorie de céramique fait l’objet d’une étude détaillée. Ce travail s’est focalisé surtout sur les céramiques à glaçure plombifère d’Italie centrale. Un nouveau classement typologique est ainsi proposé à partir de céramiques issues des contextes gaulois et romains. Certaines formes récurrentes indiquent l’existence d’un commerce - certes réduit - de ce type de céramique en Méditerranée occidentale au cours des IIe et IIIe siècles. L’étude des ateliers du Latium, couplée à des analyses archéométriques et aux dernières découvertes archéologiques, permet de localiser avec précision les centres de production de céramiques à glaçure plombifère dans la région de Rome (Nuovo Mercato Testaccio et Janicule).Cette étude apporte une meilleure connaissance de la fabrication, de la chronologie, des lieux de production, de la diffusion et du statut de cette catégorie de céramique si particulière. L’échelle géographique et chronologique large permet d’entrevoir les transferts de la technique de la glaçure des ateliers d’Orient à ceux d’Occident. / This PhD thesis aims firstly at providing full documentation about the various lead-glazed potteries reported in the southern Gaul and the Rhone Valley contexts. The inventory has pointed out the existence of six ceramic production groups over a period spending between the end of the first century B.C and the middle of the third century A.D. Ceramics come from Minor Asia, northern Italy, Lyon and Saint-Romain-en-Gal’s workshops, the center of Gaul, central Italy and Capitou's workshop (Hérault). Each ceramic category is the subject of a detailed study. This work is mainly dedicated to lead-glazed ceramics of central Italy. Investigation of consumer contexts leads to re-examine the classification of these ceramics and changes dating. A new typological classification is proposed. Some recurrent forms indicate the existence of a real trade - even reduced - of this type of ceramic in western Mediterranean area during the second and third century. The work done on Lazio's workshops, coupled with archaeometric analyses and recent archaeological discoveries, allowed the precise location of lead-glazed ceramic production centres in the Rome area (Nuovo Mercato Testaccio and Janiculum).This study of lead-glazed potteries from the southern Gaul and the Rhone valley, and more generally of the western Mediterranean basin, provides a better understanding of the production, chronology, productions sites, trade and status of this so peculiar category of ceramic. This research work based on large geographical and chronological scale, allows us to understand the process of glaze technology transfer from Eastern workshops to those of the Western workshops.