The haka is a traditional ancestral war cry, dance, or challenge from the Māori people of New Zealand. It is a posture dance performed by a group, with vigorous movements and stamping of the feet with rhythmically shouted accompaniment.
War haka were originally performed by warriors before a battle, proclaiming their strength and prowess in order to intimidate the opposition, but haka are also performed for various reasons: for welcoming distinguished guests, or to acknowledge great achievements, occasions or funerals, and kapa haka performance groups are very common in schools.
According to the BBC:
Ms Armstrong, 21, was "blown away" by the performance. She said the haka was a sign of respect from her husband's best man and family not, as some have commented online, an attempt to intimidate him. "They are quite strong, the men in their family," she said.
The Star Kenya
Prince Harry pulls off the moves with ease while maintaining a look of deep concentration while taking part in a Maori Haka on his trip to New Zealand.