LE CHIESE DUPLICES DELL'ORDINE DI SAN GIOVANNI DI GERUSALEMME (SECOLI XII-XIII). TRA ICONOGRAFIA ARCHITETTONICA ED ESIGENZE FUNZIONALI

The term "duplices churches" refers to those sacred buildings that contain two superimposed worship rooms. The distinctive features of a duplex church are not only derived from its architectural form. They also affect the way the two superimposed worships rooms are used, so much so that a church can only be defined as duplex if the liturgical purpose of both floors can be demonstrated. The functional analysis (directly linked to the study of the sacral topography of the different monastery) makes it possible to demonstrate how the overlapping of two worship rooms depends on practical reasons – linked to the needs of the human groups that gravitated around the monasteries – and cannot be traced back to a real architectural iconography. Why it was decided to duplicate the sacred space and what the functions of the two superimposed rooms were, are the questions that led to the limitation of the field of investigation. In fact, by preferring the duplices churches erected or managed by the Knights of the Order of St. John of Jerusalem, it is possible to have a coherent field of investigation, on which one can draw well‑founded comparisons and fully understand the phenomenon. The study focuses on ten Hospitallers monasteries, built in Europe and Jerusalem between the early 12th century and the turn of the 13th century. Only five of these turn out to have a duplex church, while the remaining ones can be traced back to other types (tower churches, churches with emporium, churches with upper floor for secular use). Also in the case of the duplices churches, the variety of solutions adopted (formal and functional) demonstrates once again how the duplex form cannot be considered an architectural iconography, or even more the architectural iconography preferred by the Hospitallers. Duplices churches were erected to meet practical needs, first of all the need to be open to the lay population and at the same time to have a space where monks could retire in prayer. Also the morphology of the area or the existence of other buildings could lead to the duplex form, while rarer – but still proven – were the symbolic meanings.