a two-handed pole weapon that came to prominent use during the 14th and 15th centuries. [...]
[It] consists of an axe blade topped with a spike mounted on a long shaft. It always has a hook or thorn on the back side of the axe blade for grappling mounted combatants. It is very similar to certain forms of the voulge in design and usage. The halberd was usually 1.5 to 1.8 metres (5 to 6 feet) long.
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