In Gallo-Roman religion, Ambisagrus was a Gaulish god worshipped at Aquileia in Cisalpine Gaul, where he was identified with Jupiter Optimus Maximus. The name may be composed of the Proto-Celtic prefix *ambi- ('around') and root *sagro-. Dr. John Koch at the University of Wales Centre for Advanced Welsh & Celtic Studies has suggested that this Jovian epithet may originally have applied to Taranis, with allusion to the tendency of thunder near an observer to seem all-surrounding.
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