Recording and restoration of the Trigonion Tower

The historic documentation, architectural andstructural analysis and a complete proposal of restoration and reuse of theTrigonion Tower in Thessaloniki began as an interdisciplinaryproject for the purposes of the Postgraduate Interdepartmental Programme of theFaculty of Engineering at the Aristotle University of Thessaloniki entitled“Protection, Conservation and Restoration of Architectural Monuments” duringthe academic year 2006-2007. The successful approach was appreciated by the authority in charge of the monument, the 9th Ephorate of Byzantine Monuments, who committed the project team to realize the proposal. The TrigonionTower, built around the end of the15th century after the Ottoman invasion in Thessaloniki, is a unique monumentoverlooking the city from the north-east corner of its walls. The exact date of its erection as well as theidentity of the constructors have been questioned, although today itsconstruction by the Ottomans in the end of the 15th century, in order toreinforce the Byzantine walls of the city, tends to be a generally acceptedopinion. The resemblance ofTrigonion to the well-known White Tower of Thessaloniki is another issue to beconsidered as their similarities and differences could provide further clues inmatters of chronology. Despite the fact that typologically Trigonionbelongs to the cylindrical, artillery towers, it lacks typical characteristicsof this category due to the existence of the older, byzantine, quadrangulartower in its internal, a fact that did not allow the symmetrical constructionof its layout. Moreover, the presence of medieval, defensive mechanisms, likethe murder holes and the portcullis in an artillery tower of the 15th centuryunderline the role of the monument as an example of the transitional era fromthe medieval war techniques to the artillery fighting.