The PCR fortifying the Alps in the Middle Ages, involving around ten researchers (doctoral candidates, archaeologists, academics) has just completed its probationary year at the end of 2019. It was born out of the observation of the scarcity of castellology research in the south-east quarter and its aim was, on the one hand, to revitalise it but also to connect the various researchers working on this subject. He is the heir of the major research and inventories launched from the 70s onwards, such as those on earth castles, and proposes to organise the collection and synthesis of all the data accumulated on castral events in the Alpine area between Rhône and Durance. The geographical area concerned by the PCR corresponds to the medieval states of Savoie and Dauphiné and their margins (Faucigny, Genevois, Valentinois, Marquisat de Provence, Dauphiné transalpine). Six counties belonging to two regions are currently included: The Ain, Drôme, Isère, Savoie, Haute-Savoie for the Auvergne-Rhône-Alpes region and the Hautes-Alpes for the Provence-Alpes-Côte-d’Azur.Research prospects are primarily part of an overall framework for gathering data on the fortified sites in the geographical area studied in a database with a reference to the scientific dates (C14, da-chronology, etc.) known on the castral environment of our study area. The purpose of setting up this database is an online publication via a GIS. This tool will be useful both to researchers, as it will make available data that are often scattered or even inaccessible, on the national archaeological map, to those involved in heritage development and conservation, but also to the public at large who will be able to see the diversity, complexity and relevance of the medieval fortified heritage of the Alpeses.Three specific lines of research have been identified to observe the phenomenon of fortification of the Alpine mountain area in various ways:• Axis 1: First castles in the Alpine area. This topic would like to take over the file of fortifications before the year Mil or on which old occupation is known (tardo-antique, mesrovingian, Carolingian). They are in principle few in number and the wide scale of PCR will make it possible to compare the data needed to understand this period.• Axis 2: Terminology and form of fortified buildings. This problem proposes defining as precisely as possible the structures fortified in mountain areas and linking them with a legal status. This includes taking over castral motts but also buildings (or bastides) or strong houses and residences of rural and urban elites.• Axis 3: Morphology and evolution of castral assemblies. This last theme looks at the architecture of the buildings and their developments in order to restore as closely as possible the buildings of mountain castles and their functions. In addition to the organisation of PCR and the definition of scientific priorities, this year has made it possible to set up the first projects that will continue under the three-year plan. During regular quarterly meetings, an inventory of the first castles, built before Mil dansla PCR area, was drawn up, while noting that many sites were probably not detected by our inventory method. It will then be necessary to propose a new methodology in order to refine our list and to propose a summary of the location of the premierschâteaux in mountainous environments. On the other hand, the discussions and sharing on the subject of buildings led us to propose that a study day be held for 2020 to show the scale of the problem, which we had thought it had hitherto been more extensive. Finally, the basis for the chrono-typology of shooting openings has been drawn up by creating a list of suitable sites to be studied in this context and a driver for drafting notices in order to make the final result easier to publicise. The regular participation of all PCR members demonstrates its usefulness for the scientific community. The first review also highlights the need to renew research in castellology with the creation of new study tools and new inventory methods.