The Diffusion of Fired Bricks in Hellenistic Europe: A Similarity Network Analysis

Abstract

In this study, similarity networks are used to analyse the diffusion of fired bricks across Hellenistic Europe, initiated in the north Aegean in the fourth century BCE. In a similarity network, archaeological contexts with similar attributes are connected according to a predefined criterion, and the edges are interpreted as potential social or causal links. Here we allow any kind of similarity relation between brick contexts as a criterion for connection, where different kinds of attributes can be mixed. The analysis suggests that there was indeed a diffusion process, as opposed to random, independent appearances of fired bricks. This diffusion seems to have taken place in a small-world social network of builders and decision-makers, where the range of most connections was shorter than 250 km but where long-range connections were also present. The data seemingly exclude a scale-free network, in which the diffusion is governed by a few dominant hubs. An early cluster of homogeneous brick usage appears in the south-eastern part of Hellenistic Europe, as well as a late cluster in the north-west. In the late cluster, the homogenisation applies to larger constructions (public or military) than in the early cluster (mainly sepulchral), suggesting that the use of fired bricks became established at higher societal levels in the last century BCE.