In 1796, Kamehameha I, then the conqueror of all the Hawaiian Islands, except Kauai and its satellite island of Niihau, launched his first invasion of Kauai from Waianae, Oahu.
At his command were 1,200 to 1,500 canoes and around 10,000 soldiers, about half of whom were armed with muskets.
But, disaster struck about one-quarter of the way across the Kauai Channel, when Kamehameha’s armada encountered fierce winds that sank many of his canoes, forcing him to order what remained of his fleet back to Oahu.
In anticipation of still another invasion, Kauai’s King Kaumualii was then able to muster only three cannons, 40 swivel guns, and a relatively small force of soldiers in defense.
He also hired foreigners to build a small vessel, so that he might escape in it to another Pacific island or even to China in the likelihood that his meager forces would be defeated.
Meanwhile, on Oahu, Kamehameha assembled a second invasion force consisting of 7,000 Hawaiian and 50 European soldiers, most armed with muskets, and several mortars, eight cannons, 40 swivel guns, 21 armed schooners, and a large fleet of double-hulled canoes.
Yet, in 1804, as fate would have it, disaster fell upon Kamehameha a second time, when a foreign disease, likely typhoid or cholera, devastated his magnificent army.
Kaumualii was exultant, for his kingdom had been spared invasion once again.
However, Kamehameha’s determination to conquer Kauai did not end.
Thereafter, he sought a peaceful means of satisfying his ambition to rule all of the Hawaiian islands.
He proposed an alliance with Kaumualii, whereby Kaumualii’s kingdom would fall under his rule, yet with Kaumualii still retaining authority over it.
Finally, in 1810, when Kamehameha indicated he would be satisfied if Kaumualii were to acknowledge his sovereignty in person and be willing to pay him tribute, Kaumualii, dreading a third invasion, consented.
On Oahu, in April of 1810, Kaumualii and Kamehameha sealed their alliance.
Thereafter, Kaumualii would continue to rule Kauai, but as a vassal king under Kamehameha, who would not attempt to conquer Kauai again.
Source: The Garden Island