A Puzzling Religious Inscription from Medieval Tuscany: Symbology and Interpretation

At the entrance of some churches in Tuscany (Italy), the reproduction of an apparently undecipherable inscription can be found. Beginning in the 18th century, this epigraphic puzzle has originated a debate on its interpretation. This study proposes a hypothesis based on the Latin alphabet used in texts contemporary to the churches where the inscription is reproduced and a possible interpretation of the message consistent with the official religious doctrine. The proposed deciphering is extended to the full text, including some signs that were previously considered geometric forms or a specific elaboration of letters not attested in other contemporary documents.