A powerful young Celtic god, given the name Mercury by the Romans. Smertrios is also known as Mercury, but this is not really contradictory, as the Romans often misidentified Celtic gods, for instance calling several different Celtic gods Mars.
In un-Romanized Ireland this god was called Lugh, “The Shining One,” and he was known as “skilled in many arts together.”
In the tale of The Battle of Magh Tuiredh, Lugh is credited with commanding all the arts possessed by the craftsmen in the house of Nuadha, King of the Tuatha de Danann. He went to the royal court of Tara when a great feast was in progress. The doorkeeper asked him his skill and when Lugh said, “I am a wright,” the doorkeeper said he was not needed as they had a wright already. “I am a smith,” said Lugh, but the doorkeeper said the Tuatha had a smith already. So it went on, with Lugh listing his skills as harper, champion, hero, poet, historian, sorcerer, and cupbearer, but the Tuatha de Danann had all of these. Then Lugh asked, “Do you have anyone who combines all these skills?” They did not and Lugh was allowed to enter.
Lugh was worshiped elsewhere too. In Wales he was known as Lleu. His name survived in place-names such as Lugudunum (Lyons) and Luguvallum (Carlisle). The town of Lyons was chosen by Augustus as the capital of the province of Gaul and the location of his own annual festival on August 1. This evidently continued an existing Celtic festival that was dedicated to the town’s divine patron, not only the emperor Augustus but also the god Lugh. This is the ancient harvest festival celebrated in the Celtic world as Lughnasad, “The Commemoration of Lugh.”
Lugh was a more civilized and sophisticated god than the Daghda. He had a spear and a sling instead of the Daghda’s heavy club. He was a lively and colorfiol figure, youthful, athletic, and handsome, and able to defeat malevolent beings from the Otherworld. His epithet “of the long arm” may refer to the fact that he could kill at a distance with a slingshot or a spear, or it may have the more general meaning that his power had a long reach.