1. Did Vikings ever wear horned helmets in battle?
No surviving Viking Age combat helmet has horns. The most complete helmets recovered from the Viking world—the tenth-century Gjermundbu helmet from Ringerike, Norway, and the Anglo-Scandinavian Yarm helmet from North Yorkshire—are practical rounded iron caps fitted with spectacles-style eye guards or nasal bars so blows glance harmlessly off the skull. Horns would catch an opponent's axe blade and wrench the wearer's neck.
Where did the confusion start? First, genuine horned bronze helmets (such as the Viksø helmets found in a Danish peat bog) do exist in Scandinavian museums—but they date to the Nordic Bronze Age around 1000 BCE, nearly two thousand years before the Viking Age. Second, small seventh-to-ninth-century ritual depictions (on the Oseberg tapestry and Vendel helmet press-plates) show ceremonial dancers wearing bird-headed or horned headdresses linked to Odinic cult. In 1876, costume designer Carl Emil Doepler put horned helmets onto characters in Richard Wagner's Der Ring des Nibelungen at Bayreuth, cementing the visual cliché worldwide.