The last battle of Anne of Brittany: Solving mass grave through an interdisciplinary approach (paleopathology, biological anthropology, history, multiple isotopes and radiocarbon dating)

Abstract

Mass graves are usually key historical markers with strong incentive for archeological investigations. The identification of individuals buried in mass graves has long benefitted from traditional historical, archaeological, anthropological and paleopathological techniques. The addition of novel methods including genetic, genomic and isotopic geochemistry have renewed interest in solving unidentified mass graves. In this study, we demonstrate that the combined use of these techniques allows the identification of the individuals found in two Breton historical mass graves, where one method alone would not have revealed the importance of this discovery. The skeletons likely belong to soldiers from the two enemy armies who fought during a major event of Breton history: the siege of Rennes in 1491, which ended by the wedding of the Duchess of Brittany with the King of France and signaled the end of the independence of the region. Our study highlights the value of interdisciplinary approaches with a particular emphasis on increasingly accurate isotopic markers. The development of the sulfur isoscape and testing of the triple isotope geographic assignment are detailed in a companion paper [13].

Multi-isotope variation reveals social complexity in Viking Age Norway

“…Interestingly, unlike in other parts of western Europe, there is no evidence here, based on oxygen data alone, of migrants from the more northerly regions migrating further south in Norway—if anything the opposite appears to be the case here ( Leggett, 2021a ). However, when combined with the limited existing 87 Sr/ 86 Sr data from Naumann’s work in double-isotope provenancing models ( Figure 7 ), possible regions of origin are surprisingly varied and do include northern regions of Fennoscandia ( Bataille et al., 2021 ; Colleter et al., 2021 ; Naumann, 2014 ; Price and Naumann, 2014 ).…”

“…For some of the individuals, we have additional strontium data from previous work ( Naumann, 2014 ; Price and Naumann, 2014 ) which in addition to δ 18 O gives geological provenancing information for individual mobility ( Figures 6 and 7 ). The application of single (δ 18 O) and double-isotope (δ 18 O and 87 Sr/ 86 Sr) predictive origin models in R ( Bataille et al., 2021 ; Colleter et al., 2021 ; R Development Core Team, 2021 ) was used to generate illustrative maps of potential regions of childhood origins for the individuals analyzed here and add greater interpretative power to the isotopic data. For a full explanation of the models, see Bataille et al., (2021) ( Bataille et al., 2021 ).…”

“…This is meant to aid archaeological interpretations, and whilst it can rule out certain areas, caution must be used when interpreting possible regions highlighted, and “brewing and stewing” effects should still be considered. Modifications were made to the equations used by Bataille et al., (2021) ( Bataille et al., 2021 ) – namely the use of the Chenery conversion equations for drinking water, as we felt they were more conservative, and a change to their code for plotting site geographic coordinates as their original code did not work as published ( Bataille et al., 2021 ; Chenery et al., 2012 ; Colleter et al., 2021 ). These and all other graphs of isotopic data produced here were produced using free and Open Source R (version 4.0.4) and RStudio (version 1.4.1106) ( R Development Core Team, 2021b ; RStudio Team, 2021c ).…”

Silver Linings at the Dawn of a “Golden Age”

“…The benefit of multi-isotope research is not new, but researchers are only beginning to combine multiple isotopes in isoscape mapping and spatial assignments (see Bataille et al, 2021 for an example and discussion). Depending on what underpins spatial variability in other isotope systems (e.g., geology, anthropogenic emissions, and coastal proximity for sulfur, or climate and topography for oxygen or hydrogen), multi-isotope approaches can reinforce (or alternatively, challenge) inferences made from strontium isotopes alone (e.g., Leach et al, 2009;Crowley et al, in press;Czére et al, in press;Neil et al, 2020;Colleter et al, 2021;Funck et al, 2021;Reich et al, 2021;Wooller et al, 2021). Trace element studies, such as those using lead, can also provide more nuanced insights (e.g., Shaw et al, 2016;Moore et al, 2020;Walser et al, 2020).…”

“…Themes in historical archaeology, such as agricultural intensification, urbanism, and industrialization, are just now beginning to receive attention by isotope bioarchaeologists as researchers seek to better understand changes in animal and human diet that characterized these major transitions (see discussion in Britton and Guiry, 2020). Not only are strontium isotope studies in archaeology now increasingly focusing on historic periods, researchers are also increasingly employing truly interdisciplinary approaches (see Colleter et al, 2021 for an example). Future work in historical isotope archaeology must continue to go beyond just referring to historical sources or documents and remain on this trajectory of cross-disciplinary collaboration, where studies are co-designed, and interpretations made within frameworks meaningful for all fields involved.…”