Modelling terrestrial route networks to understand inter-polity interactions (southern Etruria, 950-500 BC)

Abstract

Ancient regional routes were vital for interactions between settlements and deeply influenced the development of past societies and their "complexification". At the same time, since any transportation infrastructure needs some level of inter-settlement cooperation to be established, they can also be regarded as an epiphenomenon of social interactions at the regional scale. Here, we propose to analyze ancient pathway networks to understand the organization of cities and villages located in a certain territory, attempting to clarify whether such organization existed and if so, how it functioned.To address such a question, we chose a quantitative approach. Adopting network science as a general framework, by means of formal models, we try to identify how the collective effort that produced the terrestrial infrastructure was directed and organized. We selected a paradigmatic case study: Iron Age southern Etruria, a very well-studied context, with detailed archaeological information about settlement patterns and an established tradition of studies on terrestrial transportation routes, perfectly suitable for testing new techniques. The results of the modelling suggest that a balanced coordinated decision-making process was shaping the route network in Etruria, a scenario which correlates well with the picture elaborated by different scholars using a more traditional technique.

Patterns of Etruscan Urbanism

“…The more probable outcome, even in the absence of Rome, would have been a long-standing rivalry between equally ranked cities, where no individual city was able to overcome its equally large neighbour. This is a pattern imprinted on the political landscape, as we have seen earlier in the paper (compare also discussion in Fulminante and Stoddart, 2013;Fulminante et al, 2017;Prignano et al, 2019;Fulminante, in press).…”

Complex networks to understand the past: the case of roads in Bourbon Spain

“…18 Optimal networks depend on the city they refer to. Calculation of the optimal networks for three cities: Barcelona, Seville and Valladolid using the procedure described in the text, based on the Dijkstra (1959) algorithm 9 Other approaches such as those based on route optimization on cost maps (Voigtlaender and Voth 2019) or network generation (Faber 2014;Prignano et al 2019) have the disadvantage of only taking into account local optimization, so they have difficulty in assessing whether intermediate nodes should be incorporated even if they increase the length of the route or consider weightings for the nodes. 10 Except in the case of the unweighted model that only transport costs were used.…”

Comparing spatial networks: A one-size-fits-all efficiency-driven approach

“…Given a certain layout of the nodes in space, there are multiple connectivity patterns presenting approximately the same total length, L tot = i,j a ij d ij . Among the plethora of spatial network models available in the literature [4,19,[24][25][26][27], we selected the Minimum Spanning Tree (MST) [2], the Greedy Triangulation (GT) [28], the Equitable Efficiency Model (EEM) [29], and the Gastner-Newman model (GN) [19] as benchmarks, thus encompassing a wide spectrum of possibilities. Then, we built the MST, GT, EEM, and GN networks on random distributions of nodes in a unit square and compute their E glob and E loc .…”

“…Latium Vetus/Southern Etruria: The networks of trails among settlements between 950 and 509 BC (Iron Age) in two regions of Italy, namely: Latium Vetus [33] and Southern Etruria [29]. Nodes represent settlements, while an edge denotes a direct route connecting them.…”

“…In this section, we present the essential traits of the Equitable Efficiency Model (EEM) introduced by Prignano et al in [29]. EEM is a growth model which builds networks from empty and static spatial node layouts.…”