Spolia, defined as reused architectural elements in constructions, constitute a diachronic practice extending from antiquity to modern times, mostly denoting war trophies. Their application was related to multiple parameters including technical, economic, aesthetic, symbolic, and cultural aspects. In all cases, the reuse of high-quality, processed materials could be associated with the diachronic principles of sustainability. Therefore, spolia can be characterized as precursors of the contemporary circular resource management strategies adopted in the constructional sector. In the present paper, the spolia identified in nine monuments in Thessaloniki, dated throughout a wide period of 1.5 millenniums (from the Roman to the Ottoman era), were studied. Analysis results, regarding their location, functional use, type, origin, geometric characteristics, and technology, were statistically processed and concluding remarks were assessed. Their application was classified into three principal categories related to structural, functional, and symbolic usage, rendering spolia material mediators between successive historic periods, through which memory, cultural identity, and architectural continuity can be foreseen in the city of Thessaloniki.
Pachta et al. (Fri,) studied this question.