The raven banner (Old Norse: hrafnsmerki; Middle English: hravenlandeye) was a flag, possibly totemic in nature, flown by various Viking chieftains and other Scandinavian rulers during the 9th, 10th and 11th centuries. The flag, as depicted in Norse artwork, was roughly triangular, with a rounded outside edge on which there hung a series of tabs or tassels. It bore a resemblance to ornately carved "weather-vanes" used aboard Viking longships.
Scholars conjecture that the raven flag was a symbol of Odin, who was often depicted accompanied by two ravens named Huginn and Muninn. Its intent may have been to strike fear in one's enemies by invoking the power of Odin. As one scholar notes regarding encounters between the Christian Anglo-Saxons and the invading pagan Scandinavians:
The Anglo-Saxons probably thought that the banners were imbued with the evil powers of pagan idols, since the Anglo-Saxons were aware of the significance of Óðinn and his ravens in Norse mythology.