An altformangesverd (literally, “too many swords”) is a type of polearm developed in medieval Europe. It was first developed by Viking raiders impressed by mutli-bladed polearms in use elsewhere in Europe, such as the voulge-guisarme. Seeking to improve on the design, a Viking blacksmith referred to in written records as One Hand Knut developed a polearm where the entire surface was covered with sharp blades, hooks, and knives.

Although the altformangesverd was feared by opponents in battle, it was considered too unwieldy for long-term use and soon fell out of favor. The altformangesverd could only be held by warriors with mailed gloves to protect their hands from the many blades, and even then, self-inflicted cuts, limb loss, and disembowelment were common.

There was a brief period of resurgent altformangesverd use during World War II, as small groups of Norwegians on snowshoes attempted to use homemade altformangesverds to fight the occupying Nazi army. This effort was largely unsuccessful.