Kohala on the Island of Hawai‘i was likely settled in its windward valleys about A.D. 1100–1200 and along the leeward shoreline between A.D. 1200 and 1400.
Kamakau noted, in early Hawaiʻi “The parents were masters over their own family group … No man was made chief over another.” Essentially, the extended family was the socio, biological, economic and political unit.
Because each ʻohana (family) was served by a parental haku (master, overseer) and each family was self-sufficient and capable of satisfying its own needs, there was no need for a hierarchal structure.
With such a small (but growing) population based on the family unit, society was not so complicated that it needed chiefs to govern or oversee the general population.
Kamakau states that there were no chiefs in the earliest period of settlement but that they came “several hundred years afterward … when men became numerous.”
Ancient household units in Hawai‘i are represented archaeologically by clusters of small stone and earthen structures, including terraces, enclosures, and small semicircular stone shelters.
The mauka field system was likely established between A.D. 1200 and 1400.
Marion Kelly noted dryland field systems were one of the three noted subsistence production intensification techniques initiated by the early Hawaiians (along with walled fishponds and lo‘i kalo (irrigated, terraced pondfields for taro cultivation)).
Farmers found, farmed and intensified production on lands that were poised between being too wet and too dry. Archaeological evidence of intensive cultivation of sweet potato and other dryland crops is extensive, including walls, terraces, mounds and other features.
In the mauka field system, larger residential features are identifiable by constructed terraces with stout stone walls on the upslope (windward) side of these structures, which served as windbreaks and anchored the perishable thatch hale.
Natural bedrock outcrops were also used for habitation and were modified with abutting stone-faced terraces and stacked stone-wall enclosures.
Archaeological evidence indicates a chronology of household expansion (and, by inference, to population growth, as well as increased managerial presence and a desire to produce higher yields) spanning three temporal periods between A.D. 1400 and 1800.
The overall pattern is one of an exponential rate of increase in residential features, with the greatest number of such features existing in temporal period 3 (A.D. 1650–1800), just before European contact.
The pattern of early expansive construction (the phase 1 alignments and trails) indicates that the area was developed over time as farmers established new fields and farmsteads.
During phase 2, additional residential clusters were established, and the ahupua‘a was subdivided with new agricultural alignments inserted predominantly between the new residences and trails.
The lands were progressively subdivided with new trails and alignments (such as phase 3 constructions), as preexisting territorial segments were carved into smaller units.
This chronology fits well with the previously established chronology of agricultural system intensification which shows a pattern of late intensification (marked by increased field alignment construction) after A.D. 1650.
Archaeological evidence of intensive cultivation of sweet potato and other dryland crops is extensive, including walls, terraces, mounds and other features.
The fields throughout the Kohala system were oriented parallel to the elevation contours and the walls (and perhaps kō (sugar cane) planted on them) would have functioned as windbreaks from the trade winds which sweep down the slopes of the Kohala mountains.
Configured in this way, the walls would also have reduced evapotranspiration and – with heavy mulching – retained essential moisture for the crops. This alignment of fields also conserved water by retaining and dispersing surface run-off and inhibited wind erosion and soil creep.
The main development of the Kohala field system took place AD 1450-1800. By the late-1600s the lateral expansion of the field system had been reached, and by AD 1800 the system was highly intensified.
The process of intensification involved shortened fallow periods, and agricultural plots divided into successively smaller units.
The archaeological map of the Kohala field system depicts over 5,400-segments of rock alignments and walls with a total length of nearly 500-miles.
The fields begin near the north tip of the island very close to the coast. The western margin extends southward at an increasing distance from the coast, with the eastern margin at a higher elevation and also an increasing distance from the coast.
From north to south the field system is more than 12-miles in length. At its maximum, it is more than 2.5-miles in width.
Scientists speculate that this farming did not just support the local population, but was also used by Kamehameha to feed the thousands of warriors under his command in his conquest of uniting the islands under a single rule.
Based on experimental plantings, if only half of the Kohala Field System was in production in one year, it could be producing between 20,000 to 120,000-tons of sweet potato in one crop.
Archaeologists conclude that the higher frequency of residences within the core area of the field system, as well as the initial expansion of field system trails and alignments that demarcate major land divisions, suggests that this process was managed from the outset.
On the basis of ethnohistoric documents from the 18th and 19th centuries, they note that such management was performed by elites, who were required to generate surplus at the level of the ahupua‘a.
Population growth, coupled with increased management and tribute requirements, supported the increasingly hierarchical sociopolitical system of archaic states that emerged in Hawai‘i ca. A.D. 1600–1800
The system was abandoned shortly after European contact in the early- or mid-19th century. (Lots of information here is from Field and Kirch.)