There are suggestions, however, that horned helmets may have been used by Víkingar for ceremonial purposes and rituals. A tapestry found in the Oseberg ship burial, and dated around the 9th century (at the height of the Viking age), shows a man wearing a horned helmet
More significant is the Vendal period Öland bronze plate (late 6th to early 9th century) shown above, which depicts a Úlfhéðinn wearing a wolf pelt, together with the god Óðinn, who happens to be wearing a... horned helmet!
HORNED HELMET AND THE CHURCH
Christians have long associated horns with the devil. It is therefore no surprise that the Church started depicting Víkingar with horned helmets, in order to make them look more horrible, barbaric, and ultimately, more evil. After all, the Church had to justify the persecution and oppression of this people during forced Christianization...
Their SYMBOL: THE HORNED HELMET
The logo was symbolic, something that looked like a trophy (one must earn the right to use the NØRSKK badge). An emblem that could be used as a weapon when worn as a pendant. A symbol of strength. They furher wanted a symbol that would also express a clear opposition to the forced Christianization of their people.
So their logo is a horned helmet, and was use it indiscriminately... Including on the Norse gods, because of its symbolism, its bad ass aspect, and the fact that Óðinn was, in fact, depicted with horns during the Viking age!