Roman Catholic Diocese of Dax

His cult, at least, existed in the time of Charlemagne, as is proved by a note (in a later hand) of the Wolfenbüttel manuscript of the Hieronymian Martyrology.

[2] The oldest account of his martyrdom is in a breviary of Dax, dating from the second half of the thirteenth century, but the author knows nothing of the martyr's time period or the reasons for his death.

[3] Excavations near Dax proved the existence of a Merovingian cemetery on the site of a church which, it is claimed, was dedicated to St. Vincent by Bishop Gratianus.

Degert in the course of this publication succeeded in rectifying certain errors in the episcopal lists of the Gallia christiana and of Father Eubel in Hierarchia catholica.

During the Great Schism, Dax, which was part of Aquitaine, belonged to the Kings of England (in 1378 Richard II).