The natural recurrence of seismic events and the widespread presence of historic buildings located in earthquake-prone areas characterise a large part of the Italian and European territory. The strategic problem of safeguarding the cultural heritage involves not only civil protection, but also the sphere of research and conservation. Architecture constitutes a preferential pathway whose analysis makes it possible to propose types of intervention and restoration, through the pre- and post- earthquake interventions implemented by communities over the centuries. This process is carried out through a series of traditional and innovative methods of the humanities, with the support of scientific and technological tools. This reflection appears even more interesting when we move from architecture to much more complex and interconnected organisms from the construction, urban planning and social points of view, such as historic centres. Studying the seismicity of historic centres, and more specifically the effects of specific earthquakes on the documentary and material components that constitute their framework, becomes a very useful element from various points of view (social, economic, political, etc.). Archaeoseismological analysis, historical-archival study, survey and structural analysis are linked and transformed into a complex of extremely useful information to be used, for example, for the knowledge of the study context from a historical point of view, but also with reference to future analyses of the vulnerability of architecture in function of the planning of restoration work or, from a seismological point of view, for a better knowledge of seismic history and its concrete effects on buildings and the fabric of the city. The previous reflections formed the basis and found their concrete application in the conception and development of the project PROTECT - Knowledge for PReventiOn. TEChnique for reparing seismic damage from medieval period To modern era. The project, finds its genesis and evolution through a dual perspective: historical-archaeological and methodological. On the one hand, the work, which is currently in progress, will be synthesised in the realisation of an operational protocol for historic centres, based on different types of analysis of a multidisciplinary nature at differentiated levels of depth, which will make it possible to record and document individual buildings, street fronts, aggregates and urban centres according to specific methodological criteria defined according to the different objectives of the researches. On the other hand, the project, by means of an in-depth archaeoseismological analysis of a broad and circumscribed study context, such as the historic centre of Siena, will attempt to produce data of a historical nature that will provide preliminary information in an attempt to fill a temporal gap, concentrated in the medieval period, regarding the use, systematic or otherwise, of architectural expedients to respond to preventive or constructive needs in reference to earthquakes.