The central claim in "L'Or de Rennes" was that Saunière found parchments proving that the lineage of the "last" Merovingian king, Dagobert II, assassinated on 23 December 679, did not die with him as had previously been thought. His son was presumed to have escaped the massacre and took refuge at Rennes-le-Château, where he founded a line of descent before being buried in 758 in the church crypt. These genealogical documents implicated to an exceptional degree the Priory of Sion, a secret organisation working behind the scenes ever since the Carolingian and Capetian usurpations for the recognition of the legitimacy of the Merovingian line of descent to the throne of France. Pierre Plantard claimed to be descended from Dagobert II.