The frontier of medieval warfare between Christian and Muslim armies in southern Spain provides a surprisingly powerful explanation of current low-density settlement patterns in those regions. This is the central finding of research by Daniel Oto-Peralías (University of Saint-Andrews), recently presented at the Royal Economic Society’s annual conference in March 2018.
His study notes that Southern Spain is one of the most deserted areas in Europe in terms of population density, only surpassed by parts of Iceland and the northern part of Scandinavia. It turns out that this outcome has roots going back to medieval times when Spain’s southern plateau was a battlefield between Christian and Muslim armies.
The study documents that Spain stands out in Europe with an anomalous settlement pattern characterised by a very low density in its southern half. Among the ten European regions with the lowest settlement density, six are from southern Spain (while the other four are from Iceland, Norway, Sweden and Finland).
On average only 29.8% of 10km2 grid cells are inhabited in southern Spain, which is a much lower percentage than in the rest of Europe (with an average of 74.4%). Extreme geographical and climatic conditions do not seem to be the reason for this low settlement density, which the author refers to as ‘Spanish anomaly’.
After ruling out geography as the main explanatory factor for the ‘Spanish anomaly’, the research investigates its historical roots by focusing on the Middle Ages, when the territory was retaken by the Christian kingdoms from Muslim rule.
The hypothesis is that the region’s character as a militarily insecure frontier conditioned the colonisation of the territory, which is tested by taking advantage of the geographical discontinuity in military insecurity created by the Tagus River in central Spain. Historical ‘accidents’ made the colonisation of the area south of the Tagus River very different from colonisation north of it.
The invasions of North Africa’s Almoravid and Almohad empires converted the territory south of the Tagus into a battlefield for a century and a half, this river being a natural defensive border. Continuous warfare and insecurity heavily conditioned the nature of the colonisation process in this frontier region, which was characterised by the leading role of the military orders as agents of colonisation, scarcity of population and a livestock-oriented economy. It resulted in the prominence of castles and the absence of villages, and consequently, a spatial distribution of the population characterised by a very low density of settlements.
The empirical analysis reveals a large difference in settlement density across the River Tagus, whereas there are no differences in geographical and climatic variables across it. In addition, it is shown that the discontinuity in settlement density already existed in the 16th and 18th centuries, and is not therefore the result of migration movements and urban developments taking place recently. Preliminary evidence also indicates that the territory exposed to the medieval ranching frontier is relatively poorer today.
Thus, the study shows that historical frontiers can decisively shape the economic geography of countries. Using Medieval Spain as a case study, it illustrates how the exposure to warfare and insecurity – typical in medieval frontiers– creates incentives for a militarised colonisation based on a few fortified settlements and a livestock-oriented economy, conditioning the occupation of a territory to such an extent to convert it into one of the most deserted areas in Europe. Given the ubiquity of frontiers in history, the mechanisms underlined in the analysis are of general interest and may operate in other contexts.