[en] In 943, a pagan king called Setric arrived with a fleet on the Seine, seeking to ‘take over thewhole area without a grant from the king’ and to bring the young Richard and his RouenNorthmen back ‘to the worship of idols, and to bring back pagan rites’. But this was not to bebecause the young Carolingian king Louis IV d’Outremer was quickly on the scene and engagedSetric and his dux Turmod in battle. Louis’s mounted forces were victorious and both Setric andTurmod were killed. As the great French historian Philippe Lauer said : ‘La défaite du vikingSetric et du renégat Turmod est un événement important dans l’histoire de l’établissementdes Normands en Neustrie’. The mystery examined in this article is, who was this pagan kingSetric (ON Sigtryggr) who had been sent to Valhalla? And where had he come from —Yorkor Denmark? It is shown that whilst a Danish origin for King Setric cannot be completelyexcluded, the equation of a King Sihtric of York with King Setric on the Seine is more likelyand is supported by a plethora of onomastic, chronological, numismatic and contextual evidence.