It was nearing the end of the Heian period in Japan. The battle of Kawasaki was the first major battle of the Early Nine Years’ War (Zenkunen War) (1051-1063.) (The fighting lasted for twelve years (or nine if you subtract short periods of ceasefire and peace.))
The war was fought between the forces of the powerful Abe clan of the far northeast of the main island of Honshū, led by Abe no Sadato, and those of the Minamoto clan, acting as agents of the Imperial Court, and led by Minamoto no Yoriyoshi and his son Yoshiie.
In 1062, Minamoto no Yoriyoshi, along with his son, led an assault on an Abe fortress on the Kuriyagawa. They diverted the water supply, stormed the earthworks and stockade, and set the fortress aflame. After two days of fighting, Sadato surrendered.
At about this time, the seiitaishogun or shōgun became de facto rulers of Japan through powerful regional clans with support from samurai (bushi) serving as the military nobility.
Europe was at war as well; on September 28, 1066, William (William the Conqueror) of Normandy (Northern France) landed in England on Britain’s southeast coast, with approximately 7,000 troops and cavalry.
He then marched to Hastings; on October 14, 1066 William defeated King Harold (England) at the Battle of Hastings. After further military efforts, William was crowned king (the first Norman King of England) on Christmas Day 1066.
At the end of the century, Europe saw the first of the Crusades, launched on November 27, 1095 by Pope Urban II; it was a military expedition by Roman Catholic Europe to regain the Holy Lands taken in the Muslim conquests of the Levant, ultimately resulting in the recapture of Jerusalem in 1099. (Between 1095 and 1291 there were seven major crusades.)
Stuff was happening in the Pacific, as well.
Using stratigraphic archaeology and refinements in radiocarbon dating, recent studies suggest it was about this same time that “Polynesian explorers first made their remarkable voyage from central Eastern Polynesia Islands, across the doldrums and into the North Pacific, to discover Hawai‘i.” (Kirch)
“Most important from the perspective of Hawaiian settlement are the colonization dates for the Society Islands and the Marquesas, as these two archipelagoes have long been considered to be the immediate source regions for the first Polynesian voyagers to Hawai‘i. …”
“In sum, the southeastern archipelagoes and islands of Eastern Polynesia have a set of radiocarbon chronologies now converging on the period from AD 900–1000.” (Kirch)
Research indicates human colonization of Eastern Polynesia took place much faster and more recently than previously thought. Polynesian ancestors settled in Samoa around 800 BC, colonized the central Society Islands between AD 1025 and 1120 and dispersed to New Zealand, Hawaiʻi and Rapa Nui and other locations between AD 1190 and 1290. (Hunt; PVS)
With improved radiocarbon dating techniques and equipment to more than 1,400-radiocarbon dated materials from 47 islands, the model considers factors such as when a tree died rather than just when the wood was burned and whether seeds were gnawed by rats, which were introduced by humans. (PVS)
“There is also no question that at least O‘ahu and Kauai islands were already well settled, with local populations established in several localities, by AD 1200.” (Kirch)
Late and rapid dispersals explain remarkable similarities in artifacts such as fishhooks, adzes and ornaments across the region. The condensed timeframe suggests assumptions about the rates of linguistic evolution and human impact on pristine island ecosystems also need to be revised. (PVS)
While Europeans were sailing close to the coastlines of continents before developing navigational instruments that would allow them to venture onto the open ocean, voyagers from Fiji, Tonga and Samoa began to settle islands in an ocean area of over 10 million square miles.
The settlement took a thousand years and involved finding and fixing in mind the position of islands, sometimes less than a mile in diameter on which the highest landmark was a coconut tree. By the time European explorers entered the Pacific Ocean in the 16th century almost all the habitable islands had been settled for hundreds of years.
The voyaging was all the more remarkable in that it was done in canoes built with tools of stone, bone and coral. The canoes were navigated without instruments by expert seafarers who depended on their observations of the ocean and sky and traditional knowledge of the patterns of nature for clues to the direction and location of islands. (Kawaharada; PVS)
The canoe hulls were dug out from tree trunks with adzes or made from planks sewn together with a cordage of coconut fiber twisted into strands and braided for strength. Cracks and seams were sealed with coconut fibers and sap from breadfruit or other trees.
An outrigger was attached to a single hull for greater stability on the ocean; two hulls were lashed together with crossbeams and a deck added between the hulls to create double canoes capable of voyaging long distances.
The canoes were paddled when there was no wind and sailed when there was; the sails were woven from coconut or pandanus leaves. These vessels were seaworthy enough to make voyages of over 2,000 miles along the longest sea roads of Polynesia, such as the one between Hawai‘i and Tahiti.
And though these double-hulled canoes had less carrying capacity than the broad-beamed ships of the European explorers, the Polynesian canoes were faster: one of Captain Cook’s crew estimated a Tongan canoe could sail “three miles to our two.”
By the time Europeans arrived in Hawai‘i in the 18th-century, voyaging between Hawai‘i and the rest of Polynesia had ceased for more than 400 years, perhaps the last voyager being Pā’ao or Moʻikeha in the 14th-century. The reason for the cessation of voyaging is not known.
However, after the 14th-century, the archaeological evidence reveals a dramatic expansion of population and food production in Hawai‘i. Perhaps the resources and energies of the Hawaiian people went into developing their ‘āina; and ties with families and gods on the islands to the south weakened. (Kawaharada; PVS) (Lots of information here from Kirch, Kawaharada and Polynesian Voyaging Society.)