Economic and socio-cultural consequences of changing political rule on human and faunal diets in medieval Valencia (c. fifth–fifteenth century AD) as evidenced by stable isotopes

Abstract

This paper explores the impact of changing religious political rule on subsistence within a single city through time using stable isotope analysis of human and animal bone collagen. The diet and economy of the medieval city of Valencia (Spain) are examined over a 1000-year period during successive periods of Visigothic, Muslim and Christian rule. Bulk stable isotope analysis of carbon (δ 13 C) and nitrogen (δ 15 N) was carried out on 67 humans and 47 animals sampled from several archaeological sites dating between the fifth and fifteenth centuries AD. Terrestrial C 3 resources dominated the diet in all periods. However, an increase in consumption of C 4 plants (e.g. millet, sorghum) and/or marine resources is detected among individuals dating to the Islamic period. Differences in the isotopic values of humans and animals between the three periods indicate a significant dietary diversity during the Islamic phases (eleventh to thirteenth century), compared with the earlier Visigothic phase (fifth-seventh century) and the later Christian phase (fourteenth and fifteenth century). Observed diachronic changes in isotopic results provide evidence for a shift in diet and subsistence, particularly during the Muslim and later Christian periods. This is linked with change in population and economic focus. Dietary diversity among Muslim individuals is hypothesised to indicate the polyculture that was reflected in varied Islamic agricultural practices and the presence of potential migrants from elsewhere in the Islamic world.

The effect of diet and sociopolitical change on physiological stress and behavior in lateRoman‐EarlyByzantine (300–700AD) and Islamic (902–1,235AD) populations from Ibiza, Spain

“…The same may be true of the urban individual. Prior analysis of medieval diet on mainland Spain has also linked differences in the consumption of C 4 resources to social status or migration (Alexander et al, 2015, 2019). However, it remains unknown if δ 13 C also correlates with phenotypic variation in mainland groups.…”

“…Oil, nuts, fruit, pulses and legumes supplemented the predominantly cereal‐based diet. Both isotopic data and historic accounts further indicate that upper class individuals consumed more meat than lower class individuals (Alexander et al, 2019; Jiménez‐Brobeil, Laffranchi, Maroto, López Sánchez, & Delgado, 2016). The type and quantity of meat consumed also likely varied diachronically.…”

“…This study focuses on the relationship between diet, stress, and behavior. Previous isotopic studies of diet have demonstrated diachronic change and inter‐individual variability in diet throughout the Late Roman‐Early Byzantine (LREB) and the Medieval Islamic period (Alaica et al, 2019; Alexander, Gutiérrez, Millard, Richards, & Gerrard, 2019; Dury et al, 2018; Fuller, Márquez‐Grant, & Richards, 2010; Márquez‐Grant, Fuller, & Richards, 2003; Nehlich, Fuller, Márquez‐Grant, & Richards, 2012; Pickard et al, 2017). Other lines of evidence also suggest political, economic, and cultural change across these periods (Costa, 2019c; Ferrer Abárzuza, 2019a; Gurrea & Martín, 2000; Ramon, 1986).…”

“…Isotopic studies confirm greater consumption of C 4 crops in Islamic Ibizan populations (Alaica et al, 2019; Dury et al, 2018; Fuller et al, 2010; Nehlich et al, 2012; Peña‐Chocarro et al, 2019; Pickard et al, 2017). However, the greater isotopic diversity of Islamic individuals may also reflect migration, because isotopic signatures of certain individuals may reflect migration from locations where cultivation of C 4 crops was more extensive (Alexander et al, 2019; Dury et al, 2018; Fuller et al, 2010; Pickard et al, 2017). Thus, it remains unclear whether higher δ 13 C values of Islamic populations reflect increased cultivation of C 4 crops, an increase in the number of migrants, or both.…”

“…Although this study focuses on Ibiza, comparing dietary trends to those seen in mainland archeological populations places Ibizan dietary patterning into a larger context. The most noticeable similarity between the mainland and Ibiza is the association between Islamic rule and greater reliance on C 4 foods (Alexander et al, 2019; Alexander, Gerrard, Gutiérrez, & Millard, 2015; Salazar‐García et al, 2014). As hypothesized for Ibizan populations, C 4 signatures may reflect the cultivation of new crops, a greater proportion of migrants from areas in which these crops were more extensively cultivated, or some combination of these factors.…”