The dictionary defines ‘unite’ as “to join together to do or achieve something; to cause (two or more people or things) to be joined together and become one thing; and to become joined together as one thing.”
The suggestion is that to ‘unite’ is a positive, beneficial thing.
Most say Kamehameha ‘united’ the Islands; however, it wasn’t very ‘positive’ during the process, for either conqueror or conquered.
In the Islands, over the centuries, the islands weren’t under single rule. Leadership sometimes covered portions of an island, sometimes covered a whole island or groups of islands.
Island rulers, Aliʻi or Mōʻī, typically ascended to power through familial succession and warfare. In those wars, Hawaiians were killing Hawaiians; sometimes the rivalries pitted members of the same family against each other.
At the period of Captain Cook’s arrival (1778-1779), the Hawaiian Islands were divided into four kingdoms: (1) the island of Hawaiʻi under the rule of Kalaniʻōpuʻu, who also had possession of the Hāna district of east Maui; (2) Maui (except the Hāna district,) Molokai, Lānaʻi and Kahoʻolawe, ruled by Kahekili; (3) Oʻahu, under the rule of Kahahana; and (4) Kauai and Niʻihau, Kamakahelei was ruler.
“At that time Kahekili was plotting for the downfall of Kahahana and the seizure of Oahu and Molokai, and the queen of Kauai was disposed to assist him in these enterprises.”
“The occupation of the Hana district of Maui by the kings of Hawaii had been the cause of many stubborn conflicts between the chivalry of the two islands, and when Captain Cook first landed on Hawaii he found the king of that island absent on another warlike expedition to Maui, intent upon avenging his defeat of two years before, when his famous brigade of eight hundred nobles was hewn in pieces.” (Kalākaua)
Kamakahelei was the “queen of Kauai and Niihau, and her husband was a younger brother to Kahekili, while she was related to the royal family of Hawaii. Thus, it will be seen, the reigning families of the several islands of the group were all related to each other, as well by marriage as by blood. So had it been for many generations. But their wars with each other were none the less vindictive because of their kinship, or attended with less of barbarity in their hours of triumph.” (Kalākaua)
“By this time nearly a generation of the race had passed away, subsequently to their discovery by Cook. How much of their strength had been exhausted by wars and the support of armies, and how much by new and terrible diseases, it is not easy to estimate. The population was greatly diminished, and the residue unimproved in morals.” (Bingham)
By the time of Cook’s arrival (1778,) Kamehameha had become a superb warrior who already carried the scars of a number of political and physical encounters. The young warrior Kamehameha was described as a tall, strong and physically fearless man who “moved in an aura of violence.” (NPS)
“Before the conquest of Kamehameha, the several islands were ruled by independent kings, who were frequently at war with each other, but more often with their own subjects. As one chief acquired sufficient strength, he disputed the title of the reigning prince.”
“If successful, his chance of permanent power was quite as precarious as that of his predecessor. In some instances the title established by force of arms remained in the same family for several generations, disturbed, however, by frequent rebellions … war being a chief occupation …” (Jarves)
The impress of his mind remains with his crude and vigorous laws, and wherever he stepped is seen an imperishable track. He was so strong of limb that ordinary men were but children in his grasp, and in council the wisest yielded to his judgment. He seems to have been born a man and to have had no boyhood. (Kalākaua)
He was always sedate and thoughtful, and from his earliest years cared for no sport or pastime that was not manly. He had a harsh and rugged face, less given to smiles than frowns, but strongly marked with lines indicative of self-reliance and changeless purpose. (Kalākaua)
He was barbarous, unforgiving and merciless to his enemies, but just, sagacious and considerate in dealing with his subjects. He was more feared and admired than loved and respected; but his strength of arm and force of character well fitted him for the supreme chieftaincy of the group, and he accomplished what no one else could have done in his day. (Kalākaua)
A later battle at ʻIao is described as, “They speak of the carnage as frightful, the din and uproar, the shouts of defiance among the fighters, the wailing of the women on the crests of the valley, as something to curdle the blood or madden the brain of the beholder. (Fornander)
The Maui troops were completely annihilated, and it is said that the corpses of the slain were so many as to choke up the waters of the stream of lao, and that hence one of the names of this battle was “Kepaniwai” (the damming of the waters). (Fornander)
Then, a final battle of conquest took place on Oʻahu. Kamehameha landed his fleet and disembarked his army on Oʻahu, extending from Waialae to Waikiki. … he marched up the Nuʻuanu valley, where Kalanikūpule had posted his forces. (Fornander)
At Puiwa the hostile forces met, and for a while the victory was hotly contested; but the superiority of Kamehameha’s artillery, the number of his guns, and the better practice of his soldiers, soon turned the day in his favour, and the defeat of the O‘ahu forces became an accelerated rout and a promiscuous slaughter. (Fornander) Estimates for losses in the battle of Nuʻuanu (1795) ranged up to 10,000. (Schmitt)
“It is supposed that some six thousand of the followers of this chieftain (Kamehameha,) and twice that number of his opposers, fell in battle during his career, and by famine and distress occasioned by his wars and devastations from 1780 to 1796.” (Bingham)
Vancouver was appalled by the impoverished circumstances of the people and the barren and uncultivated appearance of their lands. “The deplorable condition to which they had been reduced by an eleven years war” and the advent of “the half famished trading vessels” convinced him that he should pursue his peace negotiations for “the general happiness, of the inhabitants of all the islands.” (Vancouver)
“(T)he greatest loss of life according to early writers was not from the battles, but from the starvation of the vanquished and consequential sickness due to destruction of food sources and supplies – a recognized part of Hawaiian warfare.” (Bingham)
“Whether we contemplate the horrors or the glories of the rude warfare which wasted the nation, we are not to confine our views to the struggles of armed combatants, the wounds, the reproaches, and various evils inflicted on one another …”
“… but the burden of sustaining such armies deserves attention, and the indescribable misery of the unarmed and unresisting of the vanquished party or tribe, pursued and crushed, till all danger of further resistance disappeared, must not be forgotten.” (Bingham)
Kauai was never conquered; in the face of the threat of a further invasion, in 1810, at Pākākā on Oʻahu, negotiations between King Kaumuali‘i (son of Kamakahelei) and Kamehameha I took place and Kaumualiʻi yielded to Kamehameha. The agreement marked the end of war across the Islands.
The association of Kauai into the group was bloodless; the others resulted in conquest, with the winner reaping the spoils and the loser forced to concede – with blood spilled by both sides. That was the ‘uniting’ of the Islands.