Battle of Nuʻuanu

Around the year 1792 (the exact date is unknown; the landing could have been as late as February 1795), Captain William Brown, an English merchant, landed in the harbor of Honolulu. As a maritime fur trader and gun seller, he made several voyages before from the Pacific Northwest coast to the Hawaiian islands in command of the Butterworth Squadron. Captain Brown landed several vessels on the island; the ones noted are the two sloops Prince Lee Boo and the Jackall.[4]

After landing, he made an agreement with Kahekili II (the chief of the island at that time) that he would offer his military assistance against Kamehameha for use of the harbor. Likewise, Kamehameha requested military assistance and the use of artillery from Captain George Vancouver and in exchange "ceded" the island of Hawaiʻi to Great Britain in February 1794.

The two rival chiefs never met again, as Kahekili II died in mid-1794. At this point, Kahekili's son, Kalanikupule, had control of the island of Oʻahu and his half-brother, Kaʻeokulani, had control of the islands of Kauaʻi (through his wife), Maui, Lanaʻi, and Molokaʻi.

After Kahekili's death, Kaʻeokulani decided to visit Kauaʻi, his home island. In order to accomplish this, he had to travel through the way of Oʻahu. Kalanikupule then set up trenches and earthworks on the windward side of Oʻahu, where Kaʻeokulani's canoes would pass. Both sides fought, but the battle was stopped by Kalanikupule and the two chiefs met to mourn over the death of Kahekili.

Kaʻeokulani then discovered a plot to be thrown overboard by his chiefs on the way to Kauaʻi. To resolve the issue, he proposed war against Kalanikupule. This war was called Kukiʻiahu and lasted from November 16 until December 12, 1794. He ordered his men to make a land march to where Kalanikupule was stationed. In the early part of December 1794, Kaʻeokulani's army was confronted by Kalanikupule's, along with the artillery of Captain Brown's ships. With Kaʻeokulani being outnumbered and outmaneuvered, his forces fled and scattered to the mountains. Nevertheless, Kaʻeokulani's army was destroyed.

After Kaʻeokulani's defeat, a dispute arose with Captain Brown over payment. Brown and several of his men were killed, and Kalanikupule took possession of the Jackal and the Prince Lee Boo, together with all their arms. After 3 weeks of preparation, on January 4, 1795 Kalanikupule set sail for Hawaii with a fleet of canoes and the two ships, intending to make war on Kamehameha.

But the ships' crews recaptured the vessels while they were at anchor off Waikīkī. They sailed for Hawaiʻi where they told Kamehameha all that had happened. They traded Kamehameha all of Kalanikupule's weapons, which had remained in the ships, in return for supplies.[5]

Kalanikupule had received prior warnings of the impending invasion from the chiefs of Maui and Molokaʻi and had begun building several lines of fortifications on Oʻahu. He had already begun buying muskets and cannons from European traders, but had far fewer than Kamehameha. He was also assisted by one of Kamehameha's chiefs, Kaʻiana, who defected before the battle began. Kaʻiana had fallen out of favor with Kamehameha's inner circle and feared that he was being plotted against. On the voyage to Oʻahu, his army split off from the Hawaiian armada and landed on the north side of the island. There, they began cutting notches into the Nuʻuanu mountain ridge, which would serve as gunports for Kalanikupule's cannons.

Kamehameha I had begun his campaign to unify Hawaii in 1783, but prior to 1795 had only managed to unify the Big Island. However, the civil war on Oʻahu, after Kahekili II's death left that kingdom greatly weakened.

During this time, Kamehameha had been equipping his army with modern muskets and cannon, as well as training his men in their use under direction of British sailor John Young.[6] In February 1795 he assembled the largest army the Hawaiian islands had ever seen, with about 12,000 men and 1,200 war canoes. Kamehameha initially moved against the southern islands of Maui and Molokaʻi, conquering them in the early spring. Then he invaded Oʻahu.