The Unification of Hawai'i (1782–1810) was a civil war in the Hawai'ian Islands over control of the entire island chain. At the time of European contact, the islands were divided amongst competing Ali'i, or high chiefs. The Island Hawai'i was divided into several districts, Moloka'i, Lana'i, and Kaho'olawe were united under Maui, O'ahu was independent, and Kauai ruled Ni'ihau. The feudal Ali'i often fought wars to gain land and mana, however the introduction of European weapons gave some Ali'i an advantage over others, and they began aggressively taking over their neighbors.

First the big island was consolidated by Kamehameha I after overthrowing his uncle for control of the Kona Hawaii. Meanwhile, the Kingdom of Maui invaded and conquered O'ahu. With Hawai'i united under his rule, Kamehameha eventually invaded Maui. Before he could successfully invade the last two remaining islands, the paramount Chief of Kawa'i, Kaumuali'i, negotiated a peace that submitted the islands to Hawai'ian rule.

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