The traditional Zulu weapon was a long-handled throwing spear called an assegai. It was cumbersome to carry, which limited warriors' mobility. Once it was hurled, the warrior was basically defenseless.

Battle went something like this: the warriors from an impi would line up in ceremonial dress. There would be dancing, boasting, and yelling of rude insults as one at a time, warriors came out from the line and challenged an enemy to single combat.

Shaka changed this pattern of small ritualized battles. He redesigned the assegai into the iKlwa -- a short-handled stabbing spear with a long, heavy blade. A legend quickly arose that Shaka's first iKlwa was made by a magical blacksmith in a dark forest. The name iKlwa refers to the sucking noise that the spear makes when it is drawn out of a bloody wound.

Armed with the iKlwa and a long shield, his warriors were out to kill quickly, brutally and efficiently. The killing technique was to hook the enemy's shield and wrench it aside, creating an opening for a quick spear thrust to the left armpit.

Shaka's innovation allowed the Zulus to create an empire.