The Viking weapon that was a two-handed axe with a broad crescent-shaped blade was the Dane axe.
The Dane axe, also called the Danish axe, was a large battle axe associated with Scandinavian warriors from the late Viking Age and early medieval period. Its long haft gave a fighter reach, while its broad, thin blade could deliver powerful cuts. Surviving examples and later images show that designs varied, so the term covers a family of related weapons rather than one perfectly standardized model.
The weapon became especially prominent in the 10th and 11th centuries. English and Scandinavian armies used long-hafted axes, and elite huscarls of the English king are often depicted carrying them. The axe could threaten shields, helmets, and limbs, but it was also a practical tool, making it difficult to identify every archaeological axe as a battlefield weapon.
The Dane axe should not be confused with the seax, a single-edged knife or short sword. Nor was every Viking warrior equipped with one: swords, spears, bows, and smaller axes were also common.