About Guntharic des Bourguignons, roi des Bourguignons
He was a foederatus of Valentinian III.
The Burgundians were a Germanic tribe. About 276 they were mentioned north of the Danube and about 277 they became foederati of the Romans. They settled between the Franks and the Alemanni in what is now Württemburg, but were expelled by the Alemanni in 287. They continued to live on the border of the Roman empire and came to consider themselves Romans.
According to the 4th century Roman historian, Ammianus Marcellinus, the Burgundians were descended from the Romans. The claim is typical of the claims made for other Germanic tribes who were being integrated into Roman polity. There is no evidence the Burgundians themselves took the claim seriously. There is no mention of such an origin in any post-Roman source, and the Burgundians themselves in their law code only looked back to their 4th century king Gebica, whose family provided one of the kernels of the Nibelungenlied.
Later, in the Passio Sigismundi regis, the Burgundians gained a full migration legend, bringing them from Scandinavia to the Rhineland. For Gregory of Tours, a 6th century Gallo-Roman historian, the Burgundian royal family was Visigothic. The Burgundians were related to the Goths, and came from southern Sweden or Norway via Bornholm (anciently called Burgundarholm), an island which is now part of Denmark. In the 1st century they were living in what is now Poland. The account is not borne out by archaeology.