This study aims to reconstruct the biological histories of the people buried at the Royal Chapel of Lugo Cathedral, an important religious center of NW Spain, by using anthropological, geochemical, and historical perspectives. We conducted a macroscopic and radiographic study on 955 skeletal elements, a multi-isotope (delta C-13(col), delta N-15, delta S-34(col), delta C-13(ap), delta O-18(ap)) analysis of human (n = 12) and animal (n = 4) samples, and the study of 1407 documents from the cathedral archives. There was a minimum of 15 individuals, including six subadults (<7 years), seven mature males, and one possible female. Several traumatic healed injuries, a pelvis osteochondroma, and a case of DISH have been detected. Males were enriched in N-15 (up to 15.7 parts per thousand, Delta(human-animal avg) = 5.1 parts per thousand) suggesting consumption of animal protein including freshwater fish. Cathedral documents reflect fora payments in the form of rye, eggs, poultry, sheep, pigs, and eels as well as the hiring of two physicians. All individuals, except one, lived between the 14(th) and the early 15(th) centuries and show characteristics of high standard of living. Males were likely members of the cathedral-chaplains, administrators, sacristans, but not bishops-or noblemen relatives of the former according to preserved documents. Isotopic and paleopathological study suggest that they had an active and traveling life and at least one of them had connections with Central Spain. Children were local and possibly connected to the nobility. Lugo Cathedral is a prime example about the possibilities of transdisciplinary research in the identification of lifestyle in past populations.