Where and when did the belief that Vikings wore horned helmets originate?

The closest thing to an actual horned helm that comes closest to the Viking area was probably the Vikso Helmet

Unfortunately for fans of Hagar the Horrible, it predates the Viking age by over a thousand years.

Then there’s this British thing from 700 years-ish pre-Viking.

And THEN, if you really push it, there’s this decoration from the Sutton Hoo helmet
At least that’s only pre-dating the Vikings by 200 years, but it is depicting ritual bird-headdresses on a helmet that has no horns at all.

This is the only actual example of a Skandinavian-made helmet found in Skandinavia that dates from the Viking age. Note the lack of horns.

Basically, what happened was a case of musical theatre. Wagner took Greco-Roman descriptions of barbarians (note: Greece and Rome were both kaput as empires long before the Viking age) wearing ritual horned helmets, and ran with it for costuming for his operas.

And, Bob’s your uncle, generations of people grow up thinking Vikings wear helmets while they sing about trying to kill the wabbit.

@Seek pretty much nailed this one to death, and very nicely. The horned helmet stereotype started with the Romans, who attributed such helmets indiscriminately to all kinds of Northern barbarians; later this was reinforced by some archaeologists digging up a Viking helmet near a couple of drinking horns and assuming that they had once been one piece.

Such helmets were not only impractical, they would actually be dangerous if worn in combat (a helmet with such a feature could be grabbed by an enemy who could pull the wearer off-balance. Worse yet, an overhand blow to the head could snag on the joint between the helmet and the horn, greatly increasing the chance that the blow would bite deep.) Horned helmets may be replaced by the (equally unhistorical) winged helmets, especially when the work wants to present the Vikings as noble rather than barbaric.

The myth of the horned helmet was, as Seek duly notes, later revived by Victorian/Wilhelmine-era composer/theater director Richard Wagner in his staging of his extremely popular opera/dramas concerning Nordic mythology such as the Der Ring des Nibelungen which is loosely based on the Norse sagas.

From there, the horned helmet became a common element in the hyper-romantic literature popular throughout the Victorian period and from there to silent film, then to sound and color film right up to the 1960’s when reality set in and it became a joke. But it is still seen today, nevertheless, because there is nothing cooler than a Berserker wrapped in arctic wolf-pelts topped with a bovine-horned helmet.

From Disney’s Aladdin!

Seek is right. (Not a Viking but been living amoung them for 14 years )

I blame Vicky

@Seek Was it really Wagner? That was my guess, though only because the idea pleases me.

That’s the earliest thing I’ve ever seen referring to Vikings wearing horns. I’m open to new information, though. It’s apparently well documented that Wagner took his information from Greco-Roman descriptions of barbarians, though.

What’s there to say; he was a composer, not an archaeologist.

No man at arms would wear something that idiotic into battle. You would be giving your enemy a handle to pull your head down. Any such helmet would only have been ornamental.