Viking Berserkers used highly effective weaponry to compliment their exceptional battlefield aggression. In the hands of the fearsome Vikings the Dane axe and double-sided sword hacked their way through opponents throughout a large swath of Europe.

Using techniques that are only known in Japan, it is claimed that the Japanese sword is the best instance of metalworking in the world.

The elite units of the Byzantine Army, the Varangian Guard, served as personal bodyguards to the Byzantine Emperors, and originated primarily from Scandinavia and England. Along with the prowess in combat they wielded highly effective weapons.

Eagle Warriors were the elite shock troops of the mighty Aztec Empire and they fought war the Aztec way - trained not to kill but capture their enemies. Their main weapon was the ingenious macuahuitl, which used obsidian to tear through flesh.

Just as the US Navy Seals have their super-elite Team 6, so the Spartans have their own best of the best, the Krypteia, or Secret Operations Force. As part of their initiation they must stealthily and successfully assassinate an unsuspecting target.

The Ninja, or Shinobi warrior, developed a unique set of tactics that the samurai could not employ because of their honor code. Ninjas were free to conduct what today would be described as black ops, such as assassinations, spying, and sabotage.

An elite warrior class, the Koa, emerged in Hawaii amid constant warfare between the islands and its leaders. The Koa practiced a punishing martial art called Lua and sought to enrich themselves through their vanquished enemies' life force.

The elite special forces of ancient Germany, the ‘Ghost Warriors’, had an effective array of weapons when fighting, including the spear, the club, the slingshot, and javelin.

A dagger experts explains the three different types of daggers: the stabber, the slasher, and combo slasher/stabber. Watch demonstrations of each type.

The Janissaries of the Ottoman Empire were highly trained killers taken from their homes at a young age as part of a blood tax, who distinguished themselves in battle, notably during the siege of Constantinople of 1453.

In his drive to expand his empire towards India Alexander the Great's biggest obstacle is keeping his supply lines traversing Afghanistan secure. US and British forces today face the same challenges.

At the beginning of the Battle of Shinohara in late 12th century Japan each side selects their champion for a one-on-one duel, and to the surprise of the vanquished champion his opponent reveals that she is a woman.

The Roman invasion of present-day Great Britain was similar to that of the Normandy invasion in terms of the relative scale and risks involved in an amphibious assault across the English Channel.

While the Scottish were greatly outnumbered by the English army, Sir William Wallace used the Scottish terrain to his advantage.

It is posited that 9th century Vikings conquering the kingdoms of England had the upper edge in battle because they believed that the more they killed the better their standing would be in Valhalla.

The Kung Fu Nun imitates nature to develop a figthing style that is designed to take down a bigger, stronger, and faster opponent.