On the Authenticity of a Relic: An Archaeometric Investigation of the Supposed Bread Sack of Saint Francesco of Assisi

K. L. Rasmussen, I. Degano, M. P. Colombini, F. Kjeldsen, J. van der Plicht

Research output: Contribution to journalConference articleResearchpeer-review


The relic ``the sack of Saint Francesco'' has for the first time been investigated by scientific means. The sack is kept at the Franciscan Friary of Folloni near Montella in southern Italy. According to legend, the sack appeared on the doorstep of the Friary in the winter of 1224 containing bread sent from St Francesco (St Francis of Assisi), who at that time was in France. The bread was allegedly brought to the friary by an angel. We analyzed samples of the sack to obtain a radiocarbon (C-14) date and to search for any remaining traces of bread. The C-14 date yielded a calibrated age range of AD 1220-1295 (2 sigma), which places the textile in the right timeframe according to the legend. Chemical analysis by gas-chromatography with mass spectrometric detection (GC-MS) revealed the presence of ergosterol (5, 7, 22-ergostatrien-3b-ol), a known biomarker of brewing, baking, or agriculture. In this paper we have further substantiated the validity of ergosterol as a biomarker for the past presence of bread. It appears that there is a fine correspondence between the Franciscan legend and the two most decisive scientific methods relevant for analyzing the sack. Although it is not proof, our analysis shows that the sack indeed could be authentic.
Original languageEnglish
JournalRadiocarbon: An International Journal of Cosmogenic Isotope Research
Issue number5
Pages (from-to)1425-1433
Publication statusPublished - 2017
Event8th Radiocarbon & Archaeology Symposium - Edinburgh, United Kingdom
Duration: 27. Jun 20161. Jul 2016
Conference number: 8


Conference8th Radiocarbon & Archaeology Symposium
Country/TerritoryUnited Kingdom


Dive into the research topics of 'On the Authenticity of a Relic: An Archaeometric Investigation of the Supposed Bread Sack of Saint Francesco of Assisi'. Together they form a unique fingerprint.

Cite this