Several medieval texts tell the story of an imaginary voyage of Charlemagne to Jerusalem and Constantinople. Among them, the Latin Descriptio qualiter…(11th-12th century) contains sever-al odd features, analyzed in the present paper: two curious latters, one of them containing a sequenceof gobbledygook phrases. The present paper revisits the Descriptio qualiter…’s already known sourcesof inspiration, the Translatio Sanguinis Domini from the Benedictine abbey of Reichenau and anaccount by a certain monk Benedict from the monastery Saint Andrew on Mount Soracte (bothof them dating back to the 10th century). The analysis then explores the transliteration of Greek texts in the various manuscript variants of the Descriptio qualiter…, the use of voces magicae and rudiments of spoken Greek, as well as the possible misreading of a real 9thcentury Byzantine imperial letter on papyrus kept in the monastery of Saint-Denis.