GEREON, saint, martyr. – The information concerning him is uncertain and confused. S. Gregorio di Tours recalls a splendid basilica in Cologne built in honour of 50 unknown martyrs and commonly called, on account of the beautiful mosaics that adorned it, “Ad sanctos aureos.” In the Martirologio geronimiano, 318 martyrs called “Mauri” are commemorated at Cologne on 10 October. On the preceding day, however, G. is commemorated together with 392 soldier companions, put to death by Maximian in the same Cologne, on the occasion of the war against the Bagaudae.
It seems certain that the three accounts concern the same group of martyrs. There is also a Passio from the 10th century in which it is related that G., together with 318 fellow soldiers of the Theban legion, was beheaded at Cologne and thrown into a well for refusing to sacrifice. In their honour, s. Elena had a large and beautiful basilica built, called precisely “Ad sanctos aureos.” In 1121, under Bishop Norbert, a sarcophagus was opened in the cathedral of Cologne, and it was believed that the body of G. had been found in II.