The sovereignty was hereditary, with this peculiarity, that the eldest son of the king became from his birth the sovereign.

The father governed henceforth as regent until the son was of an age to take the reins in his own hands, when the father retired.

This was the idea; but, as may be imagined, it led to various complications and difficulties, and wars between the different parts of the island and the different chiefs were frequent.
When Wallis discovered the island, in June 1767, Amo was king, or Arii-rahi (called by Cook Eare-dehi), Bereia (Cook's Obereia) being his wife.

The latter seems to have been a woman of much character, and to have practically governed the island.

The two were separated, inasmuch that they had mutually contracted other alliances, but, according to the custom of the country, without affecting their friendship.
On Wallis's appearance the warlike Tahitians at once attacked the Dolphin, but were easily defeated, and the guns and small arms with which they then for the first time made acquaintance had such an effect upon them that they speedily made peace, and recognised the superiority of Europeans.
The defeat had, however, a great effect on the prestige of Amo, whose authority rapidly diminished.