The Viking weapon that was a large double-edged axe was the Dane axe.
The Dane axe was developed and used in Scandinavia during the Viking Age and remained important into the early medieval period. It usually had a broad, thin blade mounted on a long haft, giving its user considerable reach and cutting power. Some examples have blades more than 20 centimetres wide.
The weapon appears in archaeological finds and medieval artistic representations. It is especially associated with heavily armed warriors, including elite retainers and members of the Anglo-Danish armies. Its size made it effective in formation fighting, but it required space and training to use well.
The term “Dane axe” can be misleading because the weapon was not limited to ethnic Danes. Similar large axes were used across the Viking world and by armies influenced by Scandinavian military practices. It was also not the same as a small hand axe used for ordinary work.