ABSTRACT
The Walls, still surrounding partially the old town of Thessaloniki were initially built in 315 B.C. by the king Kassandros and were completed at the time of Great Theodosius (379-395 A.D.). Nowadays, the Walls extend in kilometres within the civil grid of the modern city but their continuity has been disrupted due to partial or complete collapse at numerous locations. Historically, due to their dynamic nature, in the sense that they could be adapted in accordance with civilian needs, thus being repaired after sieges and following rules of economy and functionality where the art of war was concerned, the Walls of Thessaloniki (as those of Constantinople, Nicaea and others), did in fact changed considerably over the centuries (Bouras, 2002) following the heavy fortification requirements that arose. From the overall Byzantine Walls complex which extends in kilometres within the city, two sections (Figure 1) were chosen to be studied,
particularly: (a) a simple relatively small, essentially stand-alone part of the Walls located approximately in the center of the modern city and (b) the Walls circuit in the northern part of the Byzantine fortification. This part, which due to its size is studied more thoroughly, forms a statically independent structural system, extending from the beginning of the West Gate (namely “Pyrros Gate”) to the main East Gate along the
Eptapygriou street, near the Trigonion Tower, inclusive of the two twin gates at the East section (widened and named thereafter by Anna Palaiologina) up to the circle tower (Figures 2-5) constructed later. The particular Walls Section was encircling the Byzantine acropolis (Velenis, 1998) thus separating it from the Ancient Acropolis and it consists of numerous rectangular (primarily) and triangle defensive towers. This is essentially a monolithic and straight complex with its main axis being parallel to the East-West direction. The superstructure was constructed of masonry made by alternate bands of stones and bricks (Velenis, 1998).The masonry displays a mixture of construction methods as can be seen in Figure 3.
