Haka is the generic name for Maori dance.
It's an action chant, often described as a "War Dance", but more a chant with hand gestures and foot stamping, originally performed by Warriors before a battle, proclaiming their strength and prowess and generally abusing the opposition. Now regularly performed by New Zealand representative Rugby Union (the All Blacks) and Rugby League teams before commencing a game.
Origin of the Haka
According to Maori mythology, the Sun God, Tama-nui-to-ra, had two wives, the Summer maid, Hine-raumati, and the Winter maid, Hine takurua. The child of Tama-nui-to-ra and Hine-raumati, Tane-rore is credited with the origin of the dance.
The All Blacks haka
According to legend, the particular haka used by the All Blacks dates to 1810, when Chief Te Rauparaha of the Ngati Toa tribe was being chased by enemies. He hid in a pit, and climbed out to find someone standing over him, who, instead of killing the chief, turned out to be another chief friendly to Te Rauparaha. In relief, Te Rauparaha performed a haka, with the words It is death, it is death, it is life, it is life; this is the man who enabled me to live as I climb up step by step toward sunlight. These words are still used today.