Māori shared their world with a host of atua (gods, spirits and ghosts), inhabiting a supernatural realm entwined with and inseparable from the real world. Many atua are ancestral figures – the mana (prestige, status) of a chiefly person is derived from his descent from the atua.
The atua were easily offended and some of them were downright malevolent. The key to avoiding offence was to ensure that tapu was respected. The concept of tapu was central to Māori life. To breach or diminish tapu was a very serious matter, which had dire consequences in the real world. Many things were tapu, for example, to touch the head of a chief was a terrible breach. The tapu of a chiefly person prevent him from preparing food, because food was noa.
Tapu could be breached or diminished, and it could also be created or enhanced. Tohunga in the religious realm were extremely important in Māori society, and this kind of authority was passed down through particular lines of descent. Tohunga performed special rituals to control tapu and other spiritual forces. Tohunga and rangitira had the power to create tapu – for instance, the birds on a certain lake might be declared tapu, which would prevent anybody from harvesting them until the tapu was lifted.