Tamatoa IV (1797–1857), also known as Moe'ore Teri'itinorua Teari'inohora'i, was the King of Ra’iātea and Taha'a from 1831 until his death in 1857.

He played a significant role in the sociopolitical history of the Leeward Islands during a period marked by conflicts and political transformations.

Despite early challenges, including a turbulent period marked by widespread alcohol abuse, peace was established by mid-1832 among the chiefs of the Leeward Islands, facilitated by Queen Pomare IV.

His reign was marked by significant political shifts, including confrontations with his rival Temari'i and a brief period of deposition before his reinstatement in 1855.

The latter had been recognized as "Ari'i rahi" or supreme chief of the island of Huahine, under the protection of her uncle Puru, also known as Mahine.

At the fall of the idols, towards the end of the year 1815, a battle took place at Raiatea between Tamatoa III who supported Christianity and the fanatics of idolatry who allied themselves with Fenuapeho the chief of Tahaa who was also the regent of Pomare or Teriinohorai the grandson of Tapoa I.

[8] In the month of April 1831, Fenuapeho died at sea and the government fell into the hands of the young Pomare who became Tapoa II.

Tamatoa III moved to Vaitoare on the island of Tahaa to re-establish on their lands the families who had been expelled by Tapoa II.

He suddenly fell ill and was forced to return to Raiatea to be cared for by missionary John Williams who assisted to his death in mid-June 1831.

[17] On April 3, 1832, Tapoa II was completely defeated and wounded in a fierce battle at Vaitoare on the island of Tahaa.

Instead of following his father’s good example he sanctioned the introduction of ardent spirits[22] Shortly after the May meeting, the banful effects of the late commotions on the moral habits of the people became manifest to such an extent that the settlement of Raiatea became an entire scene of brutal intoxication with every attendant vice.

This code of laws was entitled : « O Tamatoa, raua o Teariimaevarua : E ture no Raiatea, no Tahaa, no Borabora, e no Maupiti.

[26][27] In mid-July 1844, Moeore extended political asylum to his niece Queen Pōmare IV of Tahiti, who had been completely stripped of her territory's internal sovereignty by French Rear Admiral Abel Aubert du Petit-Thouars.

[25] Adopting the trappings of Western style kingship, Tamatoa attempted to place himself above the law and exert greater control and paramountcy over the district chiefs of Raiatea.

Tamatoa's power was however, limited to his hereditary district of Opoa and he was forced to return all the land he had seized to give to his family members.

[34] A clash took place on August 23, 1853, during which Tamatoa Moeore was defeated, taken prisoner and his village of Opoa burned to the ground.