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 , 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 [ 1 ]. In addition, those records usually document the life of the leaders and not that of the physical actors of the battles. The identification of individuals buried in mass graves has therefore long benefitted from archaeological [ 2 — 4 ], anthropological [ 5 — 8 ], genomic [ 9 — 11 ] and isotopic geochemistry analyses [ 12 , 13 ]. These analyses may specify the context and causes of death wars, epidemics but without artefacts in war mass graves, the camps of the buried remain unknown.
Isotope ratios of elements incorporated at different life periods in mineralized tissue bones and teeth of an individual are likely to document geographical provenance. Here, we demonstrate, for the first time, that the combined use anthropological, pathological, historical and isotopic data, coupled with advanced isotopic models [ 1 , 14 , 15 ] and existing genetic information [ 16 ], can uncover the identity of human remains found in two Breton mass graves while one of those methods alone would have failed to reconstruct their story.
