Horned helmet

European Bronze Age and Iron Age helmets with horns are known from a few depictions, and even fewer actual finds. Such helmets mounted with animal horns or replicas of them were probably used for religious ceremonial or ritual purposes.

Early archaeological finds
A pair of bronze horned helmets from the later Bronze Age (dating to ca. 900-1100 BC) were found near Viksø, Denmark in 1942. Another early find, dating to ca. 800 BC, are two figurines of men with horned helmets, found in Zealand, Denmark.

A pre-Roman Celtic bronze helmet, dating to ca. 100 BC, was found in the River Thames, in England. Its 'horns', different from those of the earlier finds, are straight and conical. Late Gaulish helmets (ca. 55 BC) with small horns and adorned with wheels, reminiscent of the combination of a horned helmet and a wheel on plate C of the Gundestrup cauldron (ca. 100 BC), were found in Orange, France.

Migration Period
A depiction on a Migration Period (5th century) metal die from Öland, Sweden, shows a warrior with a helmet adorned with two snakes or dragons, arranged in a manner similar to horns. Decorative plates of the Sutton Hoo helmet (ca. 600 AD) depict spear-carrying dancing men wearing horned helmets. A die for striking plaques of this kind was found at Torslunda, Sweden. An engraved belt-buckle found in a seventh-century grave at Finglesham, Kent in 1965 bears the image of a naked warrior standing between two spears wearing a belt and a horned helmet; a case has been made that the much-repaired chalk figure called the "Long Man of Wilmington", East Sussex, repeats this iconic motif, and originally wore a similar cap, of which only the drooping lines of the neckguard remain. This headgear, of which only depictions have survived, seems to have fallen out of use with the end of the Migration period. There is a single depiction on a Viking Age amulet found in Uppland, Sweden that shows a figure with two snakes or dragons on its head.

In Asia, soldiers of Goguryeo, one of the Three Kingdoms of Korea, are depicted wearing helmets with large horns on top.

Middle Ages
During the High Middle Ages, fantastical headgear became popular among knights, in particular for tournaments The achievements or representations of some coats of arms, for example that of Lazar Hrebeljanovic, depict them, but they rarely appear as charges depicted within the arms themselves. It is sometimes argued that Iron Age helmets would not have been worn in battle due to the impediment to their wearer. However, impractical adornments have been worn on battlefields throughout history.

Viking Age misconception
Although horned helmets are in popular culture often associated with Vikings, there is no evidence that Viking Age Scandinavians have ever worn them. The attribution probably arose in 19th century Swedish Romanticism. The image was so widespread by the mid-20th century that the helmet logo of the Minnesota Vikings football team is a horn on each side of the helmet.

There is one other instance of a possible depiction of a Viking Age horned helmet, an illustration on a tapestry found in the Viking Age Oseberg ship burial.

Overall, there have been so few discoveries of horned helmets that it appears unlikely that Vikings really wore horned helmets to battle. The depictions of warriors could represent ritual war dances as well as actual combat. The most likely explanation is that this helmet type originated in Celtic religion, possibly related to Cernunnos, and that then it was adopted, changing the horns into snakes, by Germanic tribes during the Migration age, and continued to play a certain role in religious ritual up to the 9th century or so.