Grannus

Old French grenon ('small beard'), Old Spanish greñon ('beard') and Occitan gren ('moustache') are derived from an earlier *grennos, that is supposed to be Gaulish, but the vocalism is difficult to reconcile with the other forms.

[12] The town's hot springs with temperatures between 45 °C and 75 °C lay in the somewhat inhospitably marshy area around Aachen's basin-shaped valley region.

[12] According to Cassius Dio, the Roman Emperor Caracalla (188 AD to 217 AD) unsuccessfully sought help from Apollo Grannus—as well as Aesculapius and Serapis—during a bout of physical and mental illness, visiting the god's shrine and making many votive offerings; Dio claims that the gods refused to heal him because they knew Caracalla's intentions to be evil.

[14][citation needed] A 1st century AD Latin inscription from a public fountain in Limoges mentions a Gaulish ten-night festival of Grannus (lightly Latinized as decamnoctiacis Granni): Translation: "The vergobretus Postumus son of Dumnorix gave from his own money the Aqua Martia ("Water of Martius [or Mars]", an aqueduct[16]) for the ten-night festival of Grannus".

[3] A votive altar at Astorga invokes him after "holy Serapis" and "the many-named Isis", and before "the unvanquished Core and Mars Sagatus".