Decorative Viking Battle Axe
The axe's first incarnation was as a shaftless, stone tool before recorded history. It was mounted on antlers and wood very early on and used as a tool for cutting trees and, most likely, other people. The tool developed through the bronze age and reached one of its pinnacles among the Vikings of the 15th and 16th centuries. The battle axe was well suited to the Vikings' needs -- fairly easy to make, easy to carry and disastrous to opponents. The horrendous blows that could be made with these tip weighted swords were legendary; the axes were known to shatter shields and helmets with ease.
Like many weapons, battle axes eventually grew longer (from a little more than 3 feet in length). Polearms developed, allowing wielders to keep opponents at bay in much the same way that the rapier did for swords.
See Strongblade's Decorative Viking Battle Axe