Gold coins bearing the name king Theudebert I (533-548). Minting this type of coins used to be imperial prerogative and Theudebert was the first Merovingian king to break the rule. Unsurprisingly east Romans weren’t too happy. One can’t blame them, since IMO the imagery is rather similar to late Roman or Byzantine coins.
photo: By DALIBRI at de.wikipedia [Public domain], from Wikimedia Commons