Protocolli di conoscenza per la conservazione dei paesaggi militari medievali della Sardegna. I casi dei castelli di Gioiosa Guardia e Della Fava = Protocols of knowledge for the conservation of Sardinian medieval military landscapes. The cases of Gioiosa Guardia and Della Fava castles

Defensive structures stemmed from specific military and social needs and changed and developed their original structure according to the evolution of the military techniques. Once they lost their function and were consequently abandoned, they often became ruins. From this point of view, Sardinia is an emblematic example of stratified military landscapes, being characterized by numerous architectures of various ages, almost systematically abandoned and, in some cases, even ‘forgotten’ in the collective memory. This situation becomes particularly relevant if we refer to the system of medieval castles, objects of centuries of incurability and abuses. Although this condition is dramatic, it is however positive for knowledge purposes, since the advanced state of ruination of these defence structures allows in-depth studies, especially for building techniques, otherwise difficult to conduct. From these premises, the architectural typology of castles has been chosen for carrying out a research aimed at the definition of masonry chronotypes referring to the whole region and attributable to the period between the 12th and 19th centuries. The survey protocol used is based on a multidisciplinary and archaeometrical approach that compares the expertise of the history of architecture and restoration with the mineral-petrographic analysis. The aim is not only to identify valid chronological benchmarks referring to the various historical periods through which dating coeval buildings and specifically the so-called ‘minor architectures’, difficult to be philologically dated but it is also to reach an in-depth knowledge of such defence structures. This has paramount importance in order to ensure possible sustainable interventions, respectful of typological, technical-constructive and material peculiarities of these fabrics. The study of the castles of Gioiosa Guardia (Villamassargia - Cagliari) and Della Fava (Posada - Nuoro), built during the 12th century, is based on the application of this methodology. Located in the Southern and Northern part of the island respectively, they are the mirror of the local articulated and heterogeneous political-administrative set-up progressively outlined over the centuries. This comparison allows us to point out similarities and differences between the two structures, as well as between the different geographic contexts, outlining the type-morphological characters, masonry techniques and material peculiarities, characteristic of the chronological context investigated and to the Pisan building culture established in Sardinian territory.